424
FXUS63 KDVN 190922
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
322 AM CST TUE NOV 19 2024
KEY MESSAGES
- SEVERAL WINDY PERIODS THIS WEEK, INCLUDING TODAY WITH NEAR ADVISORY
WINDS LINGERING THROUGH MID MORNING.
- TURNING COLDER WITH THE CHANCE FOR RAIN AND SNOW SHOWERS WITH PASSING
GUSTY WINDS AND REDUCED VISIBILITY WEDNESDAY AFTERNOON AND
EVENING.
- MORE RAIN AND SNOW POSSIBLE ALONG AND EAST OF THE LOCAL AREA
ON THURSDAY.
SHORT TERM /THROUGH TONIGHT/
ISSUED AT 319 AM CST TUE NOV 19 2024
TODAY...STRONGLY OCCLUDING WRAPPED-UP CYCLONE NOTED CURRENTLY OVER
FAR SOUTHWEST MN, STILL PRODUCING TIGHT PRESSURE GRADIENT WITH AN
OCCLUDED FRONT PASSAGE TO KEEP DRIVING STRONG SFC WINDS NEAR OR
STILL AT ADVISORY CRITERIA. WITH ISALLOBARIC SURGES STILL COMING,
WILL EXTEND THE WIND ADVISORY THROUGH AT LEAST 6 AM/12Z. THE WINDS
SHOULD RELAX AS THE MORNING PROGRESSES AND THE CYCLONE COMPLEX
FOLLOWS THE STOUT PRESSURE FALLS PATHWAY UP TO NORTHERN MN BY LATE
DAY, BUT OVERALL STILL A WINDY DAY. A FEW LINGERING SHOWERS AND
SPRINKLES TO WALK OUT OF THE DVN CWA TO THE NORTH/NORTHEAST THROUGH
MID MORNING AS WELL. WITH THE IMPRESSIVE OCCLUSION PROCESS, COOLER
AIR WILL ADVECT IN FROM THE SOUTHWEST AS THE DAY PROGRESSES. BUT
UNTIL THEN, SOME CURRENT TEMPS WILL BE MILDER NOW THAN THE 12-HR
HIGHS BETWEEN 12Z-00Z. WRAP AROUND CLOUD DECK TO OCCUPY MUCH OF THE
NORTHERN 2/3'S OF THE CWA UNTIL LATE IN THE DAY, BUT EVEN THEN
CLEARING MAY BE IN DOUBT FOR THE NORTH.
TONIGHT...135+ KT UPPER JET ENERGY WILL DIG AND ROUND THE BEND,
HELPING OUT THE DEVELOPMENT OF A LARGE/LONGER WAVE UPPER TROF AND
CLOSED LOW ACRS MUCH OF THE UPPER MID CONUS BY WED MORNING. A VORT
MAX EJECTING OUT ACRS THE AREA DURING THIS PROCESS MAY PRODUCE A FEW
SPRINKLES OUT OF A PASSING CLOUD DECK ESPECIALLY ALONG AND SOUTH OF
I80 AND THEN INTO THE EAST AFTER MIDNIGHT. LOW TEMPS BY WED MORNING
SHOULD RANGE FROM THE LOWER 30S IN THE NORTHWEST, TO THE UPPER 30S
OR AROUND 40 IN THE EAST-SOUTHEAST.
LONG TERM /WEDNESDAY THROUGH MONDAY/
ISSUED AT 319 AM CST TUE NOV 19 2024
WEDNESDAY...MEDIUM RANGE MODEL ENSEMBLES IN AGREEMENT OF GYRATING
THE MAIN UPPER LOW CENTER/VORTEX ACRS THE SOUTHWESTERN GRT LKS
THROUGH THU MORNING. AS IT DOES, IT WILL SWEEP A CLIPPER-LIKE VORT
MAX ACRS THE AREA LATE WED AND INTO WED NIGHT. FCST SOUNDINGS SHOW
STEEPENING LOW TO MID LEVEL LAPSE RATES THROUGH AFTERNOON, WITH VERY
STEEP LLVL LAPSE RATES OVER 9 C/KM. WITH THE LIFT OFF THE SHORT
WAVE, AND UNSTABLE VERTICAL PROFILES FOR CONVECTIVE ROILING, THERE
WILL BE A GOOD CHANCE FOR SCTRD SHOWERS DEVELOPING AND SPREADING
ACRS THE AREA FROM THE NORTHWEST FROM LATE MORNING AND THROUGH THE
AFTERNOON AND EVENING. THERMAL PROFILES SUPPORT A RAIN-SNOW MIX, TOP-
DOWN COOLING TO MAINLY SNOW SHOWERS BY LATE AFTERNOON AND WED
EVENING. THE PROBLEM IS WITH THE STEEP LAPSE RATES, SOME SIGNS OF
SFC BUOYANCY AND INVERTED-V SOUNDING PROFILES THERE MAY BE SUPPORT
FOR SNOW SQUALL TYPE ACTIVITY WITH THE MORE ENHANCED SHOWERS. IT'S
STILL A BIT AWAY, BUT EARLY THOUGHTS OF PASSING SNOW SHOWERS
PRODUCING ENHANCED WIND GUSTS UP TO AT LEAST 40 MPH AND SHARPLY
REDUCED VISIBILITY DOWN TO A HALF MILE OR LESS. ANY SNOW
ACCUMULATIONS LOOK TO BE QUICK DUSTING OR A TENTH OF AND INCH
MAINLY ON ELEVATED SURFACES. WITH MILD GROUND TEMPS STILL, THERE IS
SOME UNCERTAINTY ON THE FLASH FREEZE OF PAVEMENT FOR A TRUE SNOW
SQUALL HIGHER IMPACT EVENT, BUT WILL HAVE TO KEEP IN MIND AS WE GET
MORE DETAILS CLOSER TO THE SHOWER EVENT. HIGH TEMPS ONLY IN THE 40S,
WITH THE FAR NORTHWEST POSSIBLY HELD IN THE UPPER 30S. WED NIGHT
LOWS IN THE LOWER 30S TO UPPER 20S.
THURSDAY...WITH THE WESTERN GRT LKS UPPER LOW PIVOTING MORE OFF TO
THE EAST-SOUTHEAST TOWARD THE EASTERN OH RVR VALLEY, THERE MAY BE
ANOTHER VORT SPOKE SPIRALING ON IT'S WESTERN FLANK PRODUCING A SWATH
OF PRECIP THIS DAY, ESPECIALLY ALONG AND EAST OF THE CWA. MODELS
VARY ON WET ACCUMULATING SNOW, TO A RAIN-SNOW MIX WITH MINOR SNOW
ACCUMS MAINLY ACRS SOUTHEAST WI AND THE NORTHEAST HALF OF IL. BRISK
NORTHWEST SFC WINDS LOOK ON TAP AS WELL IN LINGERING TIGHT CYCLONIC
PRESSURE GRADIENT, AND EXTENT OF COOL ADVECTION MAY KEEP MUCH OF THE
AREA IN THE 30S TO NEAR 40 FOR MUCH OF THE DAY.
FRIDAY THROUGH MONDAY...WEAK UPPER RIDGING TO FLATTENED WESTERLY
STEERING FLOW FOR MOST OF THIS PERIOD IN THE WAKE OF THE CYCLONE.
MAINLY DRY AND NEAR SEASONABLE TEMPS THRU SAT, THEN MINOR TEMP
MODERATION INTO EARLY NEXT WEEK. THE NEXT PRECIP MAKING IMPULSE MAY
IMPACT THE REGION LATE SUNDAY INTO MONDAY LOOKING AT ENSEMBLE WAVE
PROGRESSION IN THIS FLOW, BUT TOUGH TO DEFINE THAT FAR OUT.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 1006 PM CST MON NOV 18 2024
AREA OF SHOWERS WILL QUICKLY LIFT NORTHWARD OUT OF THE AREA
OVERNIGHT. THIS WILL BE FOLLOWED BY MVFR CIGS FOR MUCH OF THE
DAY ON TUESDAY. SOUTHEAST TO SOUTH WINDS GUSTING TO 35 TO 40 KTS
OVERNIGHT WILL BECOME WEST GUSTING TO 30 KTS ON TUESDAY.
DVN WATCHES/WARNINGS/ADVISORIES
IA...WIND ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR IAZ040>042-
051>054-063>068-076>078-087>089-098-099.
IL...WIND ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR ILZ009-
015>018-024>026-034-035.
MO...WIND ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR MOZ009-010.
SHORT TERM...12
LONG TERM...12
AVIATION...HAASE
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