Flash Flood Prediction Program
by f2p2＠udfcd.org
Time: 1215 PM Fri July 26, 2024
Forecaster: Justin Brooks
-------------------------
Internal Message Status
Flash Flood Prediction Program
-------------------------
MESSAGE 1’S HAVE BEEN ISSUED EFFECTIVE UNTIL10:00 PM
Storms have already started to impact areas along the foothills just
outside of the District where a few moderate showers have already
produced rainfall rates between 0.30”-0.50” in 10-15 minutes. The
best chance for storm activity today will begin over the next hour
with a chance for storms lasting into the evening hours. Storm motions
will generally be west to east between 10-20mph, with some erratic
storm motions likely from outflow boundaries. This will result in some
storms having the potential to anchor in place supporting clustering
thunderstorms with a threat for moderate to heavy rainfall. A quick
0.50”-0.80” in 10-20 minutes is expected, along with the
possibility for over 1.0” of rain per hour if a stronger storm
stalls over the District. Storms today may also contain hail up to
1.0”, gusty winds up to 50mph and frequent cloud-to-ground
lightning. A slight chance of showers lingers through midnight,
although the threat of heavy rainfall will likely subside by 10pm this
evening. A few off and on showers may persist through midnight with
skies gradually clearing overnight tonight. Overnight temperatures
will drop into the low 60s for the plains with mid to upper 50s along
the foothills.
STORM RAINFALL POTENTIAL AND DURATION: Typical showers will produce
0.05-0.30" total in 10-30 minutes. A moderate to strong thunderstorm
will produce rainfall rates of 0.30”-0.60” total in 10-30 minutes.
WORST CASE SCENARIO: A slow-moving thunderstorm, training of
thunderstorms cells or a large thunderstorm complex may result in up
to 1.25” of rain in 30-60 minutes.
COUNTY
MESSAGE
VALID TIMES
PRIME TIME
Lakewood
1
Current TO 1000 PM
Current TO 930 PM
Wheat Ridge
1
Current TO 1000 PM
Current TO 930 PM
Arvada
1
Current TO 1000 PM
Current TO 930 PM
the City of Aurora
1
Current TO 1000 PM
Current TO 930 PM
Arapahoe County
1
Current TO 1000 PM
Current TO 930 PM
DIA
1
Current TO 1000 PM
Current TO 930 PM
Denver County
1
Current TO 1000 PM
Current TO 930 PM
Adams County
1
Current TO 1000 PM
Current TO 930 PM
Douglas County
1
Current TO 1000 PM
Current TO 930 PM
Broomfield County
1
Current TO 1000 PM
Current TO 930 PM
Jefferson County
1
Current TO 1000 PM
Current TO 930 PM
Boulder County
1
Current TO 1000 PM
Current TO 930 PM
County-specific Quantitative
Precipitation Outlook PRECIPITATION TIME
30-Minute Rainfall
and % Probability Message
Potential
Plains
Adams
Current TO 1000 PM FRI
0.05" (60%) to 0.3" (40%) to 0.8" (20%)
ISSUED
Arapahoe
Current TO 1000 PM FRI
0.05" (60%) to 0.3" (40%) to 0.8" (20%)
ISSUED
Boulder
Current TO 1000 PM FRI
0.05" (60%) to 0.3" (40%) to 0.8" (20%)
ISSUED
Broomfield
Current TO 1000 PM FRI
0.05" (60%) to 0.3" (40%) to 0.8" (20%)
ISSUED
Denver
Current TO 1000 PM FRI
0.05" (60%) to 0.3" (40%) to 0.8" (20%)
ISSUED
Douglas
Current TO 1000 PM FRI
0.05" (60%) to 0.3" (40%) to 0.8" (20%)
ISSUED
Jefferson
Current TO 1000 PM FRI
0.05" (60%) to 0.3" (40%) to 0.8" (20%)
ISSUED
Foothills above 6500ft
Boulder
Current TO 1000 PM FRI
0.05" (90%) to 0.3" (60%) to 0.8" (30%)
ISSUED
Douglas
Current TO 1000 PM FRI
0.05" (90%) to 0.3" (60%) to 0.8" (30%)
ISSUED
Jefferson
Current TO 1000 PM FRI
0.05" (90%) to 0.3" (60%) to 0.8" (30%)
ISSUED
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.
MHFD Flood Prediction Center: 303-458-0789 F2P2 Website
[http://udfcd.org/Flash+Flood+Prediction+Program]
3 months, 1 week
Flash Flood Prediction Program
by f2p2＠udfcd.org
Time: 940 AM Fri July 26, 2024
Forecaster: Justin Brooks
-------------------------
Heavy Precipitation Outlook
Flash Flood Prediction Program
-------------------------
Slightly cooler with a chance for isolated afternoon
showers/thunderstorms
The high-pressure ridge that has anchored to the Four Corners region
finally breaks down today. This will bring a chance for a few
showers/thunderstorms this afternoon and into the early evening hours
before clearing out during the late evening.
Storms will initiate along the higher terrain around midday, moving
onto the foothills between 1-2pm this afternoon with the best chance
of storm activity within the District between 2-8pm. A couple of
rounds of storms will be possible with the first round of storms
likely having the best chance of moderate to brief heavy rainfall
today.
Generally, storm motions will be from west to east between 15-20mph
which should help limit point rainfall amounts; However, stronger
storms will have the potential to produce outflow boundaries resulting
in some erratic storm motions. These outflow boundary storms will
likely have the best potential for 0.30"-0.80” in under 30 minutes
as these storms likely pulse up and rain themselves out.
Between 8-9pm skies will gradually start to clear with mild and dry
conditions expected overnight. Temperatures will drop into the low 60s
for the plains with mid to upper 50s along the foothills.
STORM RAINFALL POTENTIAL AND DURATION: Typical showers and
thunderstorms will produce 0.05”-0.30” total in 10-30 minutes. A
moderate to strong shower/thunderstorm will produce 0.30”-0.80”
total in 10-30 minutes.
WORST CASE SCENARIO: A strong stationary thunderstorm or training of
thunderstorm cells will have the potential to produce 1.20” total in
30-60 minutes.
A LOOK AHEAD: Not much overall change in the upper-level pattern
tomorrow will bring another chance for afternoon and evening
showers/thunderstorms. Slightly less overall moisture aloft will
decrease chances for moderate to heavy rainfall for the District
tomorrow. Similar high temperatures in the low 90s. The heat returns
Sunday with highs jumping back into the upper 90s. A slight chance for
high-based showers, mainly along the foothills in the afternoon and
early evening. Hot and dry Monday with highs in the upper 90s.
LOCATION
PRIME TIME
30-Minute Rainfall
and % Probability Message
Potential
Plains
Adams
200 PM TO 800 PM
0.05" (60%) to 0.3" (30%) to 0.8" (10%)
LOW
Arapahoe
200 PM TO 800 PM
0.05" (60%) to 0.3" (30%) to 0.8" (10%)
LOW
Boulder
200 PM TO 800 PM
0.05" (60%) to 0.3" (30%) to 0.8" (10%)
LOW
Broomfield
200 PM TO 800 PM
0.05" (60%) to 0.3" (30%) to 0.8" (10%)
LOW
Denver
200 PM TO 800 PM
0.05" (60%) to 0.3" (30%) to 0.8" (10%)
LOW
Douglas
200 PM TO 800 PM
0.05" (60%) to 0.3" (30%) to 0.8" (10%)
LOW
Jefferson
200 PM TO 800 PM
0.05" (60%) to 0.3" (30%) to 0.8" (10%)
LOW
Foothills above 6500ft
Boulder
200 PM TO 800 PM
0.05" (80%) to 0.3" (40%) to 0.8" (20%)
MOD
Douglas
200 PM TO 800 PM
0.05" (80%) to 0.3" (40%) to 0.8" (20%)
MOD
Jefferson
200 PM TO 800 PM
0.05" (80%) to 0.3" (40%) to 0.8" (20%)
MOD
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.
MHFD Flood Prediction Center: 303-458-0789 F2P2 Website
[http://udfcd.org/Flash+Flood+Prediction+Program]
3 months, 1 week
Flash Flood Prediction Program
by f2p2＠udfcd.org
Time: 915 AM Thu July 25, 2024
Forecaster: Justin Brooks
-------------------------
Heavy Precipitation Outlook
Flash Flood Prediction Program
-------------------------
Hazy, Hot, and Dry Today
High-pressure continues to hold over the Four Corners region today
keeping hazy, hot and dry conditions for the District. High
temperatures will be close to record breaking with upper 90 to around
100 degrees is expected this afternoon. The current record for DIA
today is 99 degrees set in 1963.
Dry conditions are likely on the plains today with a very slight
chance for a few isolated high-based showers/thunderstorms along the
Continental Divide this afternoon with a few of those showers moving
into the foothills before mixing out onto the plains. Minimal, if any,
precipitation will be possible within the District boundary today.
Skies will gradually clear of haze throughout the day today with
clearing skies into the evening hours. Overnight will be mild and dry
with temperatures dropping into the mid 60s on the plains with upper
50s to low 60s along the foothills.
STORM RAINFALL POTENTIAL AND DURATION: A high-based shower anchored to
the higher terrain will produce a trace to 0.05” total in 10-30
minutes.
WORST CASE SCENARIO: A shower/thunderstorm can move off the higher
terrain and will have the potential to produce 0.05”-0.20” total
in 10-30 minutes.
A LOOK AHEAD: A disturbance is poised to move into the region
tomorrow, bringing a better chance of showers and thunderstorms during
the afternoon and evening for portions of the District. Storms will be
isolated in nature with some areas remaining dry. Temperatures will
decrease slightly tomorrow with highs in the mid 90s. Similar
conditions remain in place Saturday with another chance of scattered
to isolated showers and thunderstorms in the afternoon and evening
before clearing out through the overnight. Conditions dry out Sunday
with only a very slight chance for a few high-based showers and
thunderstorms, mainly along the higher terrain foothills and Palmer
Divide.
LOCATION
PRIME TIME
30-Minute Rainfall
and % Probability Message
Potential
Foothills above 6500ft
Boulder
100 PM TO 800 PM
Trace (10%) to 0.05" (5%)
NONE
Douglas
100 PM TO 800 PM
Trace (10%) to 0.05" (5%)
NONE
Jefferson
100 PM TO 800 PM
Trace (10%) to 0.05" (5%)
NONE
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.
MHFD Flood Prediction Center: 303-458-0789 F2P2 Website
[http://udfcd.org/Flash+Flood+Prediction+Program]
3 months, 1 week
Flash Flood Prediction Program
by f2p2＠udfcd.org
Time: 934 AM Wed July 24, 2024
Forecaster: Laura Smith
-------------------------
Heavy Precipitation Outlook
Flash Flood Prediction Program
-------------------------
Another Hot, Dry, and Smokey Day.
Northerly upper-level winds will continue to transport Canadian
wildfire smoke into Colorado today and tonight before smoke begins to
exit the region Thursday. Meanwhile, the expanding high-pressure
heatwave centered over the Desert Southwest region will support hot
daily high temperatures between 5 to 10 degrees above normal.
Afternoon temperatures will be in the 90s today with dewpoints in the
mid to upper 30s and precipitable water (PWAT) values around 0.60”.
These conditions will support dry weather today and tonight across the
District. Overnight lows will dip into the mid 60s with dry conditions
persisting tomorrow morning.
STORM RAINFALL POTENTIAL AND DURATION: Rainfall is not expected in the
District today.
A LOOK AHEAD: Dry and hot conditions are expected once again tomorrow
as the ridge of high-pressure remains anchored over the Desert
southwest. Temperatures will reach the mid to upper 90s with a few
areas reaching 100°F. Looking ahead to Friday, the next disturbance
will transport better moisture into the District, supporting chances
for afternoon to evening showers and thunderstorms.
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.
MHFD Flood Prediction Center: 303-458-0789 F2P2 Website
[http://udfcd.org/Flash+Flood+Prediction+Program]
3 months, 2 weeks
Flash Flood Prediction Program
by f2p2＠udfcd.org
Time: 956 AM Tue July 23, 2024
Forecaster: Laura Smith
-------------------------
Heavy Precipitation Outlook
Flash Flood Prediction Program
-------------------------
Hot, Dry, and Smokey Conditions Expected Today.
Northwesterly upper-level winds will continue to transport Canadian
wildfire smoke into Colorado through the end of the week. Meanwhile,
the heatwave centered over the Four-Corners region will begin
expanding today, encouraging hot afternoon temperatures in the upper
80s to low 90s. Dewpoints will be in the mid to upper 30s with
precipitable water (PWAT) values around 0.55”. These conditions will
support dry weather today and tonight across the District. Overnight
lows will dip into the mid 60s with dry conditions persisting tomorrow
morning.
STORM RAINFALL POTENTIAL AND DURATION: Rainfall is not expected in the
District today.
A LOOK AHEAD: Dry, hot, and smokey conditions are expected tomorrow
and Thursday as the dome of high-pressure remains anchored to the
Intermountain West. Temperatures will reach the mid to upper 90s
tomorrow with a few areas reaching 100°F on Thursday. Looking ahead
to Friday, the next disturbance will transport better moisture into
the region, supporting chances for afternoon to evening showers and
thunderstorms.
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.
MHFD Flood Prediction Center: 303-458-0789 F2P2 Website
[http://udfcd.org/Flash+Flood+Prediction+Program]
3 months, 2 weeks
Flash Flood Prediction Program
by f2p2＠udfcd.org
Time: 939 AM Mon July 22, 2024
Forecaster: Tim Tonge
-------------------------
Heavy Precipitation Outlook
Flash Flood Prediction Program
-------------------------
Warming today with isolated showers/thunderstorms this afternoon and
early evening
The active pattern has mostly passed for the time being, and chances
of measurable rainfall decrease today and for the most of the work
week. The southwestern US ridge has begun its slow return to Colorado,
and northerly flow has delivered a drier airmass from the Great Basin
to the District today. Morning dewpoints in the low 50s are forecasted
to mix down to the low 40s by the time isolated seasonal convection
starts over the high country west of the District. Storms that reach
the foothills and plains in and around the District will have
0.7”-0.8” inches of precipitable water (PWAT) to work with, and
will be capable of brief thunderstorm downpours of 0.25”-0.50” in
10-30 minutes, moving from NNW to SSE at 10-15mph. Forecast model
guidance suggests that storms in the District today are unlikely, but
enough residual moisture and energy remains in the atmosphere that the
District will have a LOW probability of message issuance during a
window between 1pm and 8pm.
STORM RAINFALL POTENTIAL AND DURATION: Typical showers and
thunderstorms will produce 0.25"-0.50" in 10-30 minutes. Stronger
storms at higher elevations may produce 0.75" in 10-30 minutes.
WORST CASE SCENARIO: A slow-moving or stationary shower or
thunderstorm may be capable of producing 1.00" in 30 minutes or less.
A LOOK AHEAD: The warming and drying trend continues tomorrow, and the
probability of message issuance will likely be NONE. There is a small
uptick in moisture as temperatures continue to warm Wednesday; likely
dry Thursday before moisture returns this weekend.
LOCATION
PRIME TIME
30-Minute Rainfall
and % Probability Message
Potential
Plains
Adams
100 PM TO 800 PM
Trace (30%) to 0.3" (20%) to 0.5" (10%)
LOW
Arapahoe
100 PM TO 800 PM
Trace (30%) to 0.3" (20%) to 0.5" (10%)
LOW
Boulder
100 PM TO 800 PM
Trace (30%) to 0.3" (20%) to 0.5" (10%)
LOW
Broomfield
100 PM TO 800 PM
Trace (30%) to 0.3" (20%) to 0.5" (10%)
LOW
Denver
100 PM TO 800 PM
Trace (30%) to 0.3" (20%) to 0.5" (10%)
LOW
Douglas
100 PM TO 800 PM
Trace (30%) to 0.3" (20%) to 0.5" (10%)
LOW
Jefferson
100 PM TO 800 PM
Trace (30%) to 0.3" (20%) to 0.5" (10%)
LOW
Foothills above 6500ft
Boulder
100 PM TO 800 PM
0.1" (30%) to 0.3" (20%) to 0.8" (10%)
LOW
Douglas
100 PM TO 800 PM
0.1" (30%) to 0.3" (20%) to 0.8" (10%)
LOW
Jefferson
100 PM TO 800 PM
0.1" (30%) to 0.3" (20%) to 0.8" (10%)
LOW
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.
MHFD Flood Prediction Center: 303-458-0789 F2P2 Website
[http://udfcd.org/Flash+Flood+Prediction+Program]
3 months, 2 weeks
Flash Flood Prediction Program
by f2p2＠udfcd.org
Time: 918 PM Sun July 21, 2024
Forecaster: Justin Brooks
-------------------------
Internal Message Status
Flash Flood Prediction Program
-------------------------
MESSAGE 1’S WILL BE ALLOWED TO EXPIRE AT 10:00 PM
Message 1’s will be allowed to expire at 10pm as the threat of
heavy rainfall has come to an end.
After a couple of rounds of showers and thunderstorms, only a few
isolated showers will persist over the District at this time. These
showers will slowly taper off from NW to SE over the next couple of
hours with skies gradually clearing through the rest of the overnight.
Mild and dry conditions are expected overnight and into daybreak
tomorrow. Temperatures will drop into the upper 50s for the plains
with low 50s along the foothills. Tomorrow will start to dry out
across the Front Range with only a few isolated showers and possibly a
high-based thunderstorms or two in the late afternoon/early evening.
STORM RAINFALL POTENTIAL AND DURATION: Minimal additional
precipitation is expected tonight and through the overnight between a
trace and 0.10” total in 10-30 minutes.
WORST CASE SCENARIO: A stronger shower/thunderstorm develops will have
the potential to produce 0.10”-0.25” total in 10-30 minutes.
COUNTY
MESSAGE
VALID TIMES
PRIME TIME
Boulder County
1
Current TO 1000 PM
Current TO 1000 PM
Jefferson County
1
Current TO 1000 PM
Current TO 1000 PM
Broomfield County
1
Current TO 1000 PM
Current TO 1000 PM
Douglas County
1
Current TO 1000 PM
Current TO 1000 PM
Adams County
1
Current TO 1000 PM
Current TO 1000 PM
Denver County
1
Current TO 1000 PM
Current TO 1000 PM
DIA
1
Current TO 1000 PM
Current TO 1000 PM
Arapahoe County
1
Current TO 1000 PM
Current TO 1000 PM
the City of Aurora
1
Current TO 1000 PM
Current TO 1000 PM
Arvada
1
Current TO 1000 PM
Current TO 1000 PM
Wheat Ridge
1
Current TO 1000 PM
Current TO 1000 PM
Lakewood
1
Current TO 1000 PM
Current TO 1000 PM
County-specific Quantitative
Precipitation Outlook PRECIPITATION TIME
30-Minute Rainfall
and % Probability Message
Potential
Plains
Adams
Current TO 1100 PM SUN
Trace (10%) to 0.1" (5%) to 0.25" (0%)
NONE
Arapahoe
Current TO 1100 PM SUN
Trace (20%) to 0.1" (10%) to 0.25" (5%)
NONE
Boulder
Current TO 1100 PM SUN
Trace (10%) to 0.1" (5%) to 0.25" (0%)
NONE
Broomfield
Current TO 1100 PM SUN
Trace (10%) to 0.1" (5%) to 0.25" (0%)
NONE
Denver
Current TO 1100 PM SUN
Trace (20%) to 0.1" (10%) to 0.25" (5%)
NONE
Douglas
Current TO 1100 PM SUN
Trace (20%) to 0.1" (10%) to 0.25" (5%)
NONE
Jefferson
Current TO 1100 PM SUN
Trace (10%) to 0.1" (5%) to 0.25" (0%)
NONE
Foothills above 6500ft
Boulder
Current TO 1100 PM SUN
Trace (10%) to 0.1" (5%) to 0.25" (0%)
NONE
Douglas
Current TO 1100 PM SUN
Trace (20%) to 0.1" (10%) to 0.25" (5%)
NONE
Jefferson
Current TO 1100 PM SUN
Trace (10%) to 0.1" (5%) to 0.25" (0%)
NONE
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.
MHFD Flood Prediction Center: 303-458-0789 F2P2 Website
[http://udfcd.org/Flash+Flood+Prediction+Program]
3 months, 2 weeks
Flash Flood Prediction Program
by f2p2＠udfcd.org
Time: 519 PM Sun July 21, 2024
Forecaster: Aaron O
-------------------------
Internal Message Status
Flash Flood Prediction Program
-------------------------
MESSAGE 1'S CONTINUE VALID UNTIL 10:00 PM
Message 1’s will continue to be valid until 10pm as the chance of
heavy rainfall remains.
After a round of moderate to strong showers and thunderstorms for
portions of the District, a few lingering showers persist toward the
north. These showers may move into the District over the next few
hours bringing some additional rainfall.
Temperatures have decreased behind the first round of showers,
however, dew points have increased into the mid 50s for some areas in
the District. These dew points would result in efficient rain
producing showers into the evening with the possibility of a shower or
two strengthening into a thunderstorm which will have good potential
for moderate to heavy rainfall.
Later this evening, a very slight chance for a few lingering showers
after 10pm with skies gradually clearing through the overnight.
Temperatures overnight will drop into the mid to upper 50s for the
plains with low 50s along the foothills.
STORM RAINFALL POTENTIAL AND DURATION: Typical showers and
thunderstorms will produce a trace-0.25” total in 10-30 minutes. A
moderate to strong shower/thunderstorm will produce 0.25-0.50” total
in 10-30 minutes.
WORST CASE SCENARIO: A strong stationary thunderstorm or training of
thunderstorm cells will have the potential to produce up to 1.00”
total in 30-60 minutes.
COUNTY
MESSAGE
VALID TIMES
PRIME TIME
Wheat Ridge
1
Current TO 1000 PM
Current TO 1000 PM
Arvada
1
Current TO 1000 PM
Current TO 1000 PM
the City of Aurora
1
Current TO 1000 PM
Current TO 1000 PM
DIA
1
Current TO 1000 PM
Current TO 1000 PM
Arapahoe County
1
Current TO 1000 PM
Current TO 1000 PM
Adams County
1
Current TO 1000 PM
Current TO 1000 PM
Denver County
1
Current TO 1000 PM
Current TO 1000 PM
Broomfield County
1
Current TO 1000 PM
Current TO 1000 PM
Douglas County
1
Current TO 1000 PM
Current TO 1000 PM
Jefferson County
1
Current TO 1000 PM
Current TO 1000 PM
Boulder County
1
Current TO 1000 PM
Current TO 1000 PM
Lakewood
1
Current TO 1000 PM
Current TO 1000 PM
County-specific Quantitative
Precipitation Outlook PRECIPITATION TIME
30-Minute Rainfall
and % Probability Message
Potential
Plains
Adams
Current TO 1000 PM SUN
Trace (50%) to 0.25" (30%) to 0.5" (20%)
ISSUED
Arapahoe
Current TO 1000 PM SUN
Trace (50%) to 0.25" (30%) to 0.5" (20%)
ISSUED
Boulder
Current TO 1000 PM SUN
Trace (40%) to 0.25" (20%) to 0.5" (10%)
ISSUED
Broomfield
Current TO 1000 PM SUN
Trace (40%) to 0.25" (20%) to 0.5" (10%)
ISSUED
Denver
Current TO 1000 PM SUN
Trace (50%) to 0.25" (30%) to 0.5" (20%)
ISSUED
Douglas
Current TO 1000 PM SUN
Trace (50%) to 0.25" (30%) to 0.5" (20%)
ISSUED
Jefferson
Current TO 1000 PM SUN
Trace (40%) to 0.25" (20%) to 0.5" (10%)
ISSUED
Foothills above 6500ft
Boulder
Current TO 1000 PM SUN
Trace (40%) to 0.25" (20%) to 0.5" (10%)
ISSUED
Douglas
Current TO 1000 PM SUN
Trace (40%) to 0.25" (20%) to 0.5" (10%)
ISSUED
Jefferson
Current TO 1000 PM SUN
Trace (40%) to 0.25" (20%) to 0.5" (10%)
ISSUED
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.
MHFD Flood Prediction Center: 303-458-0789 F2P2 Website
[http://udfcd.org/Flash+Flood+Prediction+Program]
3 months, 2 weeks
Flash Flood Prediction Program
by f2p2＠udfcd.org
Time: 126 PM Sun July 21, 2024
Forecaster: Laura Smith
-------------------------
Internal Message Status
Flash Flood Prediction Program
-------------------------
MESSAGE 1’S HAVE BEEN ISSUED EFFECTIVE UNTIL 10:00 PM
Storms have started to impact areas along the higher terrain
foothills where a few moderate showers have already produced rainfall
rates between 0.30”-0.80” in 20-30 minutes. Cooler temperatures
this morning have helped limit storm development, however as we move
into the afternoon the threat of moderate to heavy rainfall will be
possible across the entire District.
The best chance for storm activity today will begin in the next hour
with a chance for storms into the evening hours. Storm motions will
generally be NW to SE with some erratic storm motions likely from
outflow boundaries into the evening. Some storms will have the
potential to anchor in place supporting clustering thunderstorms with
a threat for longer lasting moderate to heavy rainfall.
A quick 0.50”-0.80” in 10-20 minutes is expected, along with the
possibility for over 1.0” of rain per hour if a stronger storm
stalls over the District. Storms today may also contain hail up to
1.0”, gusty winds up to 50mph and frequent cloud-to-ground
lightning.
A slight chance of showers lingers through midnight, although the
threat of heavy rainfall will likely subside by 10pm this evening. A
few off and on showers may persist overnight with skies gradually
clearing by daybreak tomorrow. Overnight temperatures will drop into
the low 60s for the plains with mid to upper 50s along the foothills.
STORM RAINFALL POTENTIAL AND DURATION: Moderate to strong
thunderstorms will have the potential to produce rainfall rates of
0.30”-0.60” in 10-30 minutes. A slow-moving thunderstorm or a
large thunderstorm complex may result in up to 1.25” of rain in
45-60 minutes.
WORST CASE SCENARIO: A strong/stationary thunderstorm or a training of
heavy showers may produce 2.00" in 30 minutes or less, resulting in
excessive runoff and possible flash flooding.
COUNTY
MESSAGE
VALID TIMES
PRIME TIME
Wheat Ridge
1
Current TO 1000 PM
200 PM TO 1000 PM
Arvada
1
Current TO 1000 PM
200 PM TO 1000 PM
the City of Aurora
1
Current TO 1000 PM
200 PM TO 1000 PM
DIA
1
Current TO 1000 PM
200 PM TO 1000 PM
Arapahoe County
1
Current TO 1000 PM
200 PM TO 1000 PM
Adams County
1
Current TO 1000 PM
200 PM TO 1000 PM
Denver County
1
Current TO 1000 PM
200 PM TO 1000 PM
Broomfield County
1
Current TO 1000 PM
200 PM TO 1000 PM
Douglas County
1
Current TO 1000 PM
200 PM TO 1000 PM
Jefferson County
1
Current TO 1000 PM
200 PM TO 1000 PM
Boulder County
1
Current TO 1000 PM
200 PM TO 1000 PM
Lakewood
1
Current TO 1000 PM
200 PM TO 1000 PM
County-specific Quantitative
Precipitation Outlook PRECIPITATION TIME
30-Minute Rainfall
and % Probability Message
Potential
Plains
Adams
Current TO 1000 PM SUN
0.3" (75%) to 0.6" (50%) to 1.2" (25%)
HIGH
Arapahoe
Current TO 1000 PM SUN
0.3" (75%) to 0.6" (50%) to 1.2" (25%)
HIGH
Boulder
Current TO 1000 PM SUN
0.3" (75%) to 0.6" (50%) to 1.2" (25%)
HIGH
Broomfield
Current TO 1000 PM SUN
0.3" (75%) to 0.6" (50%) to 1.2" (25%)
HIGH
Denver
Current TO 1000 PM SUN
0.3" (75%) to 0.6" (50%) to 1.2" (25%)
HIGH
Douglas
Current TO 1000 PM SUN
0.3" (75%) to 0.6" (50%) to 1.2" (25%)
HIGH
Jefferson
Current TO 1000 PM SUN
0.3" (75%) to 0.6" (50%) to 1.2" (25%)
HIGH
Foothills above 6500ft
Boulder
Current TO 1000 PM SUN
0.3" (80%) to 0.6" (60%) to 1.2" (40%)
HIGH
Douglas
Current TO 1000 PM SUN
0.3" (80%) to 0.6" (60%) to 1.2" (40%)
HIGH
Jefferson
Current TO 1000 PM SUN
0.3" (80%) to 0.6" (60%) to 1.2" (40%)
HIGH
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.
MHFD Flood Prediction Center: 303-458-0789 F2P2 Website
[http://udfcd.org/Flash+Flood+Prediction+Program]
3 months, 2 weeks
Flash Flood Prediction Program
by f2p2＠udfcd.org
Time: 1017 AM Sun July 21, 2024
Forecaster: Laura Smith
-------------------------
Heavy Precipitation Outlook
Flash Flood Prediction Program
-------------------------
Cool with scattered to numerous showers and thunderstorms throughout
most of day
Northeasterly upslope flow throughout the morning and early
afternoon will spark convection over the high country outside the
District sometime before Noon today. By the time this activity reaches
the District, forecasted precipitable water (PWAT) values of 1.00" and
dewpoints around 50 indicate that any storm could be capable of
producing rainfall worthy of message issuance. This convection will
spread to the foothills including areas in and around the District by
midafternoon, and reach the plains shortly thereafter. Cooler
temperatures today may keep overall convective behavior slightly
stunted, but rainfall still has potential to be significant in
isolated cases. Storms will move from NW to SE at 10-20mph, and
continued upslope flow through sunset will keep these showers in the
general area through the evening, with the potential for isolated
light showers through the late evening.
STORM RAINFALL POTENTIAL AND DURATION: Typical showers and
thunderstorms will produce 0.30"-0.60" in 15-30 minutes.
Stronger/slower moving storms will produce up to 1.25" in 30 minutes.
WORST CASE SCENARIO: A strong/stationary thunderstorm or a training of
heavy showers may produce 2.00" in 30 minutes or less.
A LOOK AHEAD: The southwestern US ridge starts to build back into
Colorado starting Monday, bringing with it a warmer and drier airmass.
This will decrease thunderstorm coverage to isolated/scattered Monday,
then isolated Tuesday and Wednesday, with temperatures reaching the
90s again by Wednesday.
LOCATION
PRIME TIME
30-Minute Rainfall
and % Probability Message
Potential
Plains
Adams
200 PM TO 1000 PM
0.3" (75%) to 0.6" (50%) to 1.25" (25%)
HIGH
Arapahoe
200 PM TO 1000 PM
0.3" (75%) to 0.6" (50%) to 1.25" (25%)
HIGH
Boulder
200 PM TO 1000 PM
0.3" (75%) to 0.6" (50%) to 1.25" (25%)
HIGH
Broomfield
200 PM TO 1000 PM
0.3" (75%) to 0.6" (50%) to 1.25" (25%)
HIGH
Denver
200 PM TO 1000 PM
0.3" (75%) to 0.6" (50%) to 1.25" (25%)
HIGH
Douglas
200 PM TO 1000 PM
0.3" (80%) to 0.6" (60%) to 1.25" (40%)
HIGH
Jefferson
200 PM TO 1000 PM
0.3" (80%) to 0.6" (60%) to 1.25" (40%)
HIGH
Foothills above 6500ft
Boulder
100 PM TO 1000 PM
0.3" (80%) to 0.6" (60%) to 1.25" (40%)
HIGH
Douglas
100 PM TO 1000 PM
0.3" (80%) to 0.6" (60%) to 1.25" (40%)
HIGH
Jefferson
100 PM TO 1000 PM
0.3" (80%) to 0.6" (60%) to 1.25" (40%)
HIGH
MONITOR NATIONAL WEATHER SERVICE FOR SEVERE WEATHER STATEMENTS.
MHFD Flood Prediction Center: 303-458-0789 F2P2 Website
[http://udfcd.org/Flash+Flood+Prediction+Program]
3 months, 2 weeks