753
FXUS63 KDMX 250001
AFDDMX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DES MOINES IA
601 PM CST MON FEB 24 2025
...UPDATED FOR THE 00Z AVIATION DISCUSSION...
KEY MESSAGES
- SCATTERED SHOWERS NORTH AND EAST LATE THIS AFTERNOON AND
EVENING, WITH ISOLATED THUNDER POSSIBLE. GUSTY WINDS MAY
DEVELOP WITH STRONGER SHOWERS OR STORMS.
- ADDITIONAL RAIN CHANCES DEVELOP TUESDAY NIGHT INTO WEDNESDAY
MORNING, FAVORING SOUTHERN AND EASTERN IOWA.
- DRY AND MILD THROUGH WEDNESDAY AND BEYOND.
DISCUSSION
ISSUED AT 249 PM CST MON FEB 24 2025
IT’S BEEN A MILD DAY ACROSS IOWA TODAY, WITH LIGHT WIND AND
WELL ABOVE NORMAL TEMPERATURES, ESPECIALLY IN SOUTHERN IOWA. AS
OF THIS WRITING, TEMPERATURES HAVE REACHED THE LOW 60S SOUTH,
THEN UPPER 40S AND 50S FURTHER NORTH. COOLEST TEMPERATURES ARE
IN NORTHERN IOWA, WHERE CLOUD COVER HAS INHIBITED SOLAR HEATING
THROUGH THE DAY. WITHIN THIS CLOUD COVER, RADAR RETURNS ARE
INDICATING LARGER HYDROMETEORS ALOFT, BUT THESE HAVE YET TO
REACH THE GROUND IN IOWA. THIS WILL CHANGE THROUGH THE COMING
HOURS, AS THE SHORTWAVE CURRENTLY SITTING OVER THE DAKOTAS
CONTINUES FURTHER SOUTHEAST TOWARD THE STATE, BRINGING SLIGHTLY
BETTER FORCING WITH IT. AS THE COLUMN ATTEMPTS TO SATURATE
THROUGH THE AFTERNOON, EXPECT A FEW SPRINKLES AND LIGHT RAIN IN
NORTHERN IOWA, FOLLOWED BY SCATTERED SHOWERS AND EVEN SOME
ISOLATED THUNDER AS THE WAVE PASSES IN THE EVENING. THIS THUNDER
WILL BE INDICATIVE OF A POCKET OF SHALLOW INSTABILITY
ASSOCIATED WITH THE APPROACHING PV ANOMALY. MUCAPE VALUES LOOK
MODEST IN THE 200 TO 500 J/KG RANGE BUT 0-6 KM SHEAR VALUES ARE
QUITE HIGH, WHICH IS TYPICAL FOR THIS TIME OF THE YEAR. HOWEVER,
THE ENTIRETY OF THIS SHEAR LIKELY WON’T BE REALIZED WITH THE
SHALLOW UNSTABLE LAYER, LIMITING THE CHANCES FOR ORGANIZED
CONVECTION. FORECAST SOUNDINGS ARE ALSO QUITE DRY, WHICH WITHOUT
MUCH INSTABILITY WILL ALSO LIMIT UPDRAFT DEVELOPMENT.
THEREFORE, NOT EXPECTING ANYTHING SEVERE AT THIS TIME,
ESPECIALLY WITH THE AMOUNT OF DRY AIR ENTRAINING INTO UPDRAFTS.
IF ANYTHING, ISOLATED GUSTY WINDS OF 35 TO 45 MPH MAY BE
POSSIBLE WITH STRONGER SHOWERS OR STORMS AS RAIN FALLS INTO THE
DRY LAYER BELOW. THESE SHOWERS/STORMS WILL MOSTLY BE CONTAINED
TO THE NORTH AND EAST, WITH THE LIKELIHOOD OF PRECIPITATION
TAPERING OFF FURTHER SOUTH AND WEST WHERE DRIER AIR IS PRESENT.
SHOWER/ISOLATED THUNDER CHANCES WILL WRAP UP BY MIDNIGHT.
DRY CONDITIONS PERSIST THROUGH TUESDAY MORNING AND INTO THE
EARLY AFTERNOON, BUT ADDITIONAL RAIN CHANCES DEVELOP AGAIN
TUESDAY EVENING AS ANOTHER WAVE QUICKLY MOVES IN BEHIND
TONIGHT’S. THE SURFACE LOW WILL TRACK TO OUR NORTH WITH A
BOUNDARY DRAGGING TO THE SOUTH AND WEST BEHIND IT. AS MOISTURE
STREAMS UP AHEAD OF THIS WAVE, MODELS HAVE BEEN PRODUCING
PRECIPITATION WITH THE THETA-E PUSH IN THE EVENING, THEN WITH
ADDITIONAL DEVELOPMENT ALONG THE FRONT THROUGH THE OVERNIGHT.
HOWEVER, THE RECENT TRENDS IN GUIDANCE HAVE DELAYED SATURATION
WITH THE THETA-E PUSH AHEAD OF THE WAVE, WITH MOST OF THE
PRECIPITATION NOW DEVELOPING TO OUR EAST AND THEN BACK ALONG THE
BOUNDARY IN SOUTHERN IOWA THROUGH THE OVERNIGHT. THEREFORE,
HAVE CUT PRECIPITATION CHANCES BACK IN THE EVENING TOMORROW WITH
MOST OF THE RAIN EXPECTED AFTER MIDNIGHT AND FAVORING THE
SOUTHERN AND EASTERN PORTIONS OF THE STATE. EVEN THEN, SOUNDINGS
INDICATE A LAYER OF DRY AIR AT THE SURFACE, WHICH WILL WORK TO
EVAPORATE ANY FALLING RAIN, THEREFORE PRODUCING ONLY A LIGHT AND
SCATTERED RAINFALL. THIS PRECIPITATION WILL PERSIST INTO
WEDNESDAY MORNING, BEFORE DIMINISHING THROUGH MID-DAY.
SLIGHTLY COOLER TEMPERATURES MOVE IN BEHIND THE BOUNDARY ON
WEDNESDAY, ALTHOUGH TEMPERATURES STILL REMAIN MILD FOR THIS TIME
OF YEAR. THROUGH THE REMAINDER OF THE WEEK, WE SEE A FEW MORE
DRY SHORTWAVE PASSAGES NEAR THE STATE. THIS INCLUDES A MORE
PROMINENT WAVE ON FRIDAY WHICH BRINGS MORE WARMER TEMPERATURES
AND BREEZY CONDITIONS. WHILE THE FORECAST IS CURRENTLY DRY,
GUIDANCE HAS VARIED SOME ON THE PLACEMENT OF THE LOW, SO CAN’T
COMPLETELY RULE OUT PRECIPITATION CLIPPING THE FAR NORTH ON
FRIDAY. THAT SAID, CHANCES APPEAR QUITE LOW AT THIS TIME.
TEMPERATURES COOL SLIGHTLY BEHIND THIS SYSTEM INTO SATURDAY, BUT
DRY AND MILD CONDITIONS PERSIST THROUGH THE END OF THE FORECAST
PERIOD.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 600 PM CST MON FEB 24 2025
VFR CONDITIONS WERE IN PLACE ACROSS IA AT 00Z WITH OVERCAST MID
CLOUDS AND SPOTTY SPRINKLES OVER THE SOUTHEAST HALF OF THE
STATE. ISOLATED HIGH-BASED SHOWERS AND THUNDERSTORMS HAD JUST
ENTERED FAR NORTHWEST IA HOWEVER, AND MAY AFFECT NORTHERN
SECTIONS, INCLUDING KMCW, THROUGH 03Z. CONFIDENCE WAS
INSUFFICIENT TO MENTION THUNDER AT KMCW AT THIS LEAD TIME HOWEVER.
ALL PRECIPITATION SHOULD EXIT THE FORECAST AREA BY MIDNIGHT
WITH MAINLY SCATTERED HIGH CLOUDINESS IN THE AFTERMATH, HOWEVER
PATCHY FOG IS ALSO POSSIBLE NORTH AS WINDS DIMINISH OVERNIGHT.
ANY FOG SHOULD DISSIPATE BY MID MORNING LEADING TO VFR
CONDITIONS FOR THE REMAINDER OF THE DAYLIGHT HOURS TUESDAY.
DMX WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION...DODSON
AVIATION...SMALL
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