842
FXUS65 KBOU 032308
AFDBOU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
508 PM MDT SAT MAY 3 2025
KEY MESSAGES
- SCATTERED SHOWERS AND A FEW STORMS TO DEVELOP OVER THE WESTERN
HALF OF THE CWA SUNDAY AFTERNOON.
- SPRING STORM BEGINS MONDAY AND CONTINUES INTO THE MIDDLE OF NEXT
WEEK. BENEFICIAL SOAKING RAIN, AND HEAVIER FRONT RANGE MOUNTAIN SNOW
QUITE LIKELY (70-80% CHANCE).
SHORT TERM /THROUGH SUNDAY/
ISSUED AT 233 PM MDT SAT MAY 3 2025
SATELLITE PICTURES ARE CURRENTLY SHOWING SOME WEAK CONVECTIVE
CLOUDINESS DEVELOPING OVER THE MOUNTAINS AND FOOTHILLS. SOME MAY
BE PRODUCING VIRGA. THE LOW LEVEL WIND FIELD ACROSS THE CWA IS
WEAK AND VARIABLE AT THIS TIME. CURRENT TEMPERATURES WERE IN THE
70S ACROSS THE PLAINS AND FOOTHILLS BELOW 7,000 FEET, WITH MAINLY
50S IN THE PARKS AND 30S & 40S IN THE MOUNTAINS.
MODELS SHOW THE UPPER RIDGE OVER THE CWA TO MOVE EASTWARD TONIGHT
INTO SUNDAY. THERE IS WEAK SOUTHERLY FLOW ALOFT OVER THE FORECAST
AREA BY SUNDAY AFTERNOON WITH AN UPPER CLOSED LOW OVER SOUTHWESTERN
ARIZONA BY 00Z LATE IN THE DAY. THERE IS BENIGN SYNOPTIC SCALE
ENERGY TONIGHT AND MUCH OF SUNDAY WITH WEAK UPWARD VERTICAL
VELOCITY PUSHING UP FROM THE SOUTH BY AFTERNOON. NORMAL DRAINAGE
LOW LEVEL WIND PATTERNS WILL PREVAIL OVERNIGHT WITH FAIRLY DEEP
SOUTHEASTERLY FLOW EXPECTED ALL DAY SUNDAY. THIS FLOW WILL
INCREASE MOISTURE A BIT BY SUNDAY AFTERNOON. QPF FIELDS SHOW
LIMITED MEASURABLE PRECIPITATION GETTING INTO THE WEST AND
SOUTHERN CWA BY SUNDAY AFTERNOON. THERE IS LIMITED CAPE PROGGED,
BUT ENOUGH TO HAVE SOME MENTION OF THUNDERSTORMS. WILL KEEP THE
30-60% POPS GOING IN THE MOUNTAINS. FOR TEMPERATURES, SUNDAY
HIGHS WILL BE SIMILAR TO TODAY'S READINGS.
LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/
ISSUED AT 233 PM MDT SAT MAY 3 2025
A STRONG SPRING STORM WILL ARRIVE ON MONDAY, WITH AN OMEGA BLOCK
CAUSING THE UPPER LEVEL CLOSED LOW TO SLOWLY TRAVEL EAST THROUGH THE
BEGINNING OF THE WEEK. BECAUSE OF THE SLOW-MOVING SYSTEM, MULTIPLE
ROUNDS OF WIDESPREAD PRECIPITATION IS EXPECTED MONDAY THROUGH
WEDNESDAY, WITH TUESDAY RECEIVING THE BULK OF PRECIPITATION. LET'S
BREAK IT DOWN BELOW:
ON MONDAY MORNING, THE UPPER LEVEL CLOSED LOW WILL MOVE INTO THE 4
CORNERS REGION, RESULTING IN SOUTHEASTERLY FLOW ALOFT. AT THE
SURFACE, STRONG SOUTHEAST WINDS, GUSTING UP TO 45 MPH, WILL ADVECT
GULF MOISTURE INTO THE REGION. SHOWERS ARE EXPECTED ACROSS THE AREA
THROUGHOUT THE DAY. SOME HIGHER RESOLUTION MODELS INDICATE A FEW
SEVERE CONVECTIVE STORMS BEHIND THE INITIAL WAVE OF SHOWERS ALONG
THE PALMER DIVIDE AND SOUTHERN PLAINS IN THE AFTERNOON. HOWEVER,
THIS IS UNLIKELY TO VERIFY AT THIS POINT AS MOST OF GUIDANCE IS
TRENDING TOWARDS A MORE STABLE ENVIRONMENT. PERHAPS IF THERE IS A
BREAK IN CLOUD COVERAGE WE COULD SEE ISOLATED STORMS. AS FOR
PRECIPITATION TYPE, RAIN WILL FALL ACROSS THE PLAINS AS TEMPERATURES
ARE EXPECTED TO REACH UP TO THE HIGH 50S/LOW 60S. FOR THE HIGH
COUNTRY, SNOWFALL IS EXPECTED FOR ELEVATIONS ABOVE 9,500 FT. WITH A
RAIN/SNOW MIX FOR ELEVATIONS ABOVE 8,000 FT.
THE UPPER LEVEL LOW WILL SLOWLY TRAVEL EAST ON TUESDAY, BUT THERE
ARE STILL UNCERTAINTIES ON THE EXACT TRACK OF THE SYSTEM. THE GEFS
IS NOW TRENDING TOWARDS A SLIGHTLY MORE SOUTHERLY TRACK INTO NEW
MEXICO THAN THE EPS, WHICH WILL AFFECT PRECIPITATION AMOUNTS
(DISCUSSED BELOW). HOWEVER, MODELS ARE IN AGREEMENT OF CONSISTENT
SOUTHEASTERLY FLOW ADVECTING MORE MOISTURE INTO THE AREA, WITH
MORE WIDESPREAD AND HEAVIER PRECIPITATION THROUGHOUT THE DAY THAN
MONDAY. TEMPERATURES ARE NOW TRENDING A SLIGHTLY WARMER AS WELL
DUE TO THE POTENTIAL FOR A MORE SOUTHERLY TRACK OF THE LOW. AS OF
RIGHT NOW, FORECASTED TEMPERATURES WOULD SUPPORT SNOW ABOVE 8,000
FT. WITH A RAIN/SNOW MIX ABOVE 7,000 FT. AREAS IN THE LOWER
FOOTHILLS AND PALMER DIVIDE WOULD MOST LIKELY SEE THE RAIN/SNOW
MIX OVERNIGHT TUESDAY, WITH LITTLE TO NO SNOW ACCUMULATION
EXPECTED. HOWEVER, IF A WARMER SOLUTION VERIFIES, SNOW LEVELS
WOULD BE SLIGHTLY HIGHER.
IN TERMS OF PRECIPITATION AMOUNTS, THE URBAN CORRIDOR AND EASTERN
SLOPES OF THE FRONT RANGE ARE STILL LIKELY TO RECEIVE THE MOST
PRECIPITATION, DUE TO THIS EVENT BEING DRIVEN BY UPSLOPE FORCING.
AREAS FURTHER EAST WILL RECEIVE LESS DUE TO AN OVERALL LACK OF
SYNOPTIC FORCING. HOWEVER, THERE ARE STILL DISAGREEMENTS OF EXACT
PRECIPITATION AMOUNTS DUE TO UNCERTAINTIES IN THE TRACK OF THE
SYSTEM. OVER THE PAST COUPLE OF RUNS, THE GEFS HAS BEEN TRENDING
TOWARDS DECREASING QPF AMOUNTS IN THE NORTHERN FRONT RANGE AND URBAN
CORRIDOR WITH A MORE SOUTHERLY TRACK OF THE LOW. IN GENERAL, THE
FRONT RANGE IS EXPECTED TO GET 1-2" OF QPF. AREAS ABOVE 9,000 FT.
HAVE THE POTENTIAL TO SEE WELL OVER A FOOT OF SNOW, WITH TRAVEL
IMPACTS LIKELY TUESDAY AND WEDNESDAY MORNING. LASTLY, IT IS
IMPORTANT TO NOTE THAT THE EPS HAS TRENDED TOWARDS HIGHER QPF
AMOUNTS JUST EAST OF THE URBAN CORRIDOR, WHICH IS REFLECTED IN
WPC'S EXPANSION OF THEIR MARGINAL RISK OF EXCESSIVE RAINFALL IN
THEIR OUTLOOK FOR TUESDAY. WE WILL CONTINUE TO MONITOR THE EVENT
AS IT UNFOLDS.
GUIDANCE IS IN GOOD AGREEMENT THAT PRECIPITATION WILL WIND DOWN
WEDNESDAY MORNING. AFTER THIS SYSTEM PASSES, TEMPERATURES SHOULD
START TO MODERATE AROUND SEASONAL AVERAGES. AN UPPER LEVEL RIDGE IS
EXPECTED TO START BUILDING OVER WESTERN UNITED STATES, WHICH WILL
BRING ABOVE NORMAL TEMPERATURES TOWARDS THE END OF THE WEEK AND INTO
THE WEEKEND. ASIDE FROM CONVECTIVE SHOWERS OVER THE MOUNTAINS IN THE
AFTERNOONS, DRY CONDITIONS SHOULD PERSIST.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 505 PM MDT SAT MAY 3 2025
VFR CONSITIONS THRU THE PERIOD. EAST WINDS WILL BECOME MORE
SOUTHERLY BY 05Z. ON SUN, LIGHT AND VARIABLE WINDS BY 13Z WILL
BECOME SOUTHEAST BY 16Z. BY 20Z, SOUTHEAST WINDS WILL INCREASE
WITH GUSTS FROM 25 TO 30 MPH.
BOU WATCHES/WARNINGS/ADVISORIES
NONE.
SHORT TERM.....RJK
LONG TERM......IDEKER
AVIATION...RPK
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page