883
FXUS65 KBOU 061837
AFDBOU
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DENVER/BOULDER CO
1237 PM MDT TUE MAY 6 2025
KEY MESSAGES
- SPRING STORM FINALLY ARRIVES IN EARNEST TODAY, BUT LATEST TRENDS
ARE FOR LESS PRECIPITATION. HEAVY, WET SNOW STILL EXPECTED IN
THE FRONT RANGE MOUNTAINS AND HIGHER FOOTHILLS.
- WARMER WEATHER MOVES INTO THE FORECAST AREA ON THURSDAY AND
CONTINUES INTO THE WEEKEND. STILL A FEW LATE DAY SHOWERS AND
STORMS MOST DAYS.
UPDATE
ISSUED AT 226 AM MDT TUE MAY 6 2025
SATELLITE SHOWS A WELL DEFINED UPPER LOW SPINNING ACROSS CENTRAL
NEW MEXICO, AND A HUGE SWATH OF RAIN AND CONVECTION EXTENDING
AROUND THE NORTHERN AND EASTERN PERIPHERY INTO MUCH OF TEXAS. AS
DISCUSSED A BIT LAST NIGHT, IT APPEARS THE LARGE AMOUNT OF LATENT
HEAT RELEASE IN TEXAS MEANS THE UPPER LOW WILL BE TAKING A LITTLE
FARTHER SOUTH TRACK. THIS MEANS WE'LL BE SEEING LESS PRECIPITATION
WITH A WEAKER UPSLOPE COMPONENT (NOW CLOSER TO 20 KTS) AND ALSO
SOME MID LEVEL DRYING COMING IN THIS EVENING FROM THE EAST.
FOR THIS MORNING, RAIN IS STILL EXPECTED TO DEVELOP AND BECOME
WIDESPREAD AS WE STILL TURN OUR WINDS FROM SOUTHERLY TO EASTERLY
THROUGH A VERY DEEP COLUMN. MOISTURE IS MORE THAN PLENTIFUL, WITH
DEWPOINTS IN THE LOWER TO MID 40S ACROSS THE PLAINS, SO ANY SORT
OF UPSLOPE SHOULD INITIATE THE HIGHER COVERAGE OF RAIN. THAT WILL
ALSO GET THE SNOW MACHINE GOING FOR THE FRONT RANGE MOUNTAINS,
WITH STRONG IVT, MODERATE UPSLOPE, AND NEARLY NEUTRAL LAPSE RATES.
SNOW LEVELS ARE STARTING OUT FAIRLY HIGH, AROUND 9,000 FEET PER
CURRENT OBSERVATIONS. HOWEVER, WITH THE PRECIPITATION RATES
INCREASING AND COLD CORE OF THE LOW GETTING A LITTLE CLOSER WE
SHOULD SEE THOSE DROP TO AROUND 8000-8500 FEET ON THIS SIDE OF THE
FRONT RANGE BY AFTERNOON. A LITTLE FURTHER DROP OF ANOTHER 500
FEET OR SO IS THEN ANTICIPATED THIS EVENING. THAT MEANS SOME
SLUSHY TRAVEL POSSIBLE IN THE HIGHER FOOTHILLS TONIGHT. WE THINK
THE BULK OF THE IMPACTS WOULD STAY ABOVE 8,000-8,500 FEET, WHERE
MORE SIGNIFICANT TOTALS ARE STILL ANTICIPATED. THE DROP IN QPF
FORECASTS IS CONCERNING TO TOTAL ACCUMULATIONS, AS LIGHTER
PRECIPITATION RATES WOULD HAVE A COMPOUNDING EFFECT ON
ACCUMULATIONS THROUGH BOTH SNOWFALL RATES AND LESS DIABATIC
COOLING. THE TRENDS ARE CERTAINLY NOT THE FRIEND OF THE SNOW
LOVERS, OR THOSE WANTING A WIDESPREAD HEAVY RAINFALL EVENT IN
LOWER ELEVATIONS. IN FACT, IT NOW APPEARS MOST OF THE I-25
CORRIDOR WILL STAY UNDER 1" FOR RAINFALL, AND 0.5" OR LESS FOR
EAST OF I-25 AND AMOUNTS ALSO TAPERING OFF MORE QUICKLY TO THE
EAST. THAT WOULD BE DUE TO THAT MID LEVEL DRY INTRUSION MENTIONED
BEFORE, AND THE MAIN SYNOPTIC ENERGY STAYING JUST SOUTH OF OUR
FORECAST AREA INTO SOUTHEAST COLORADO AND THE SOUTHERN HIGH
PLAINS.
GIVEN THE FARTHER SOUTH TRACK, PRECIPITATION INTENSITY IS EXPECTED
TO DECREASE THIS EVENING ALREADY, BUT STILL SOME UPSLOPE TO KEEP
LIGHTER RAIN/SNOW FALLING THROUGH THE NIGHT, ESPECIALLY IN THE
UPSLOPE FAVORED AREAS. A MARKED DECREASE IS STILL EXPECTED BY
WEDNESDAY MORNING AS UPSLOPE WEAKENS AND ANY SYNOPTIC SCALE
SUPPORT CONTINUES TO SHIFT AWAY FROM THE AREA. WEDNESDAY AFTERNOON
WILL STILL SEE SOME SHOWERS AROUND, GIVEN PLENTY OF RESIDUAL
MOISTURE, AND LIMITED DAYTIME HEATING AND DESTABILIZATION.
FINALLY, A COUPLE RUMBLES OF THUNDER WILL BE POSSIBLE BOTH DAYS.
WITH A LITTLE MORE HEATING TODAY ON THE PLAINS, THERE'S A VERY
SMALL 5% CHANCE OF SOMETHING TRYING TO SPIN UP INTO A SHALLOW
UPDRAFT.
FOR THE REST OF THE PERIOD, THE FORECAST IS CONSISTENT WITH A
WARMING TREND AND SCATTERED SHOWERS AND A FEW THUNDERSTORMS EACH
DAY - HIGHEST COVERAGE OVER THE MOUNTAINS.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1225 PM MDT TUE MAY 6 2025
DIFFICULT FORECAST THROUGH THE TAF PERIOD. STEADIER RAIN HAS
ALREADY PUSHED WEST OF DEN/APA, BUT SCATTERED SHOWERS ARE LIKELY
TO CONTINUE FOR THE NEXT SEVERAL HOURS. A GRADUAL INCREASE IN
COVERAGE IS ALSO LIKELY LATER THIS AFTERNOON AND EVENING, ALONG
WITH A SLIGHT CHANCE OF A THUNDERSTORM. CEILINGS WILL LIKELY
BOUNCE BETWEEN IFR TO AS HIGH AS VFR/ILS AT TIMES THROUGH MOST OF
TODAY, WITH EASTERLY WINDS DIMINISHING.
FORECAST CERTAINTY DOESN'T INCREASE TONIGHT INTO WEDNESDAY.
SURFACE WINDS WILL CONTINUE TO DIMINISH, BUT MID-LEVEL UPSLOPE
WILL ALLOW FOR AT LEAST SCATTERED SHOWERS TO CONTINUE INTO
WEDNESDAY MORNING. CEILINGS ARE LIKELY TO LOWER OVERNIGHT, WITH
SOME FOG/MIST ALSO POSSIBLE TOWARDS 12Z WEDNESDAY. CEILINGS WILL
AGAIN SLOWLY RISE TOMORROW AFTERNOON, WITH ADDITIONAL SCATTERED
SHRA/TS POSSIBLE BY LATE MORNING OR EARLY AFTERNOON.
BOU WATCHES/WARNINGS/ADVISORIES
WINTER STORM WARNING UNTIL 6 AM MDT WEDNESDAY FOR COZ033-034.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT WEDNESDAY FOR COZ035-036.
WINTER WEATHER ADVISORY UNTIL 6 AM MDT WEDNESDAY FOR COZ037.
UPDATE...BARJENBRUCH
AVIATION...HIRIS
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