064
FXUS63 KDVN 182023
AFDDVN
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
223 PM CST MON NOV 18 2024
KEY MESSAGES
- A FEW STRONG STORMS OR RAIN SHOWERS ARE POSSIBLE TONIGHT. IF A
SEVERE STORM WOULD OCCUR, THE PRIMARY RISK LOOKS TO BE WIND.
- A PROLONGED PERIOD OF WINDY CONDITIONS WILL BE SEEN THROUGH
FRIDAY. WINDS TONIGHT MAY GUST UP TO 50 MPH WITH RAIN SHOWERS
AND ANY ISOLATED THUNDERSTORM.
- CLIPPER-TYPE SYSTEMS ON WEDNESDAY AND OVER THE WEEKEND MAY
RESULT IN LIGHT SNOW SHOWERS OR FLURRIES BEING SEEN. THE VERY
WARM GROUND WILL RESULT IN ANY SNOW MELTING ON CONTACT.
SHORT TERM /THROUGH TUESDAY/
ISSUED AT 219 PM CST MON NOV 18 2024
THE MAIN RAIN SHIELD WILL EXIT THE AREA LATE THIS AFTERNOON WITH TWO
ADDITIONAL ROUNDS OF RAIN TONIGHT.
SO FAR THERE HAS BEEN NO REPORTED THUNDER OR OBSERVED LIGHTNING
ACROSS THE AREA OR IN MISSOURI. THERE IS A SMALL DRY SLOT AHEAD OF
THE CONVECTION ALONG THE KS/MO BORDER. THIS CONVECTION WHICH WOULD
HAVE THE BEST CHANCES TO PRODUCE ANY THUNDER (ALBEIT 10% CHANCE)
WOULD REACH THE AREA THIS EVENING AND MOVE RAPIDLY THROUGH
OVERNIGHT.
SUSTAINED GRADIENT WIND SHOULD BE IN THE 20-35 MPH RANGE. WINDS JUST
OFF THE SURFACE WILL INCREASE TO 60-70 MPH OVERNIGHT. THUS ANY RAIN
SHOWER OR SMALL THUNDERSTORM WOULD HAVE THE POTENTIAL TO PULL THAT
HIGHER MOMENTUM AIR DOWN AND PRODUCE LOCALIZED GUSTS OF 50 MPH.
A SHORT DURATION WIND ADVISORY FROM 7 PM TO 4 AM TUESDAY WAS
CONSIDERED. HOWEVER, GIVEN THE POTENTIAL TRANSIENT NATURE OF THE 45+
MPH WIND GUSTS WITH THE CONVECTION AND THE LIKELY GRADIENT WINDS
BEING LOWER THAN ADVISORY CRITERIA, NO WIND HEADLINES WILL BE
ISSUED. INSTEAD, A CAREFULLY WORDED SPS WILL BE ISSUED TO EMPHASIZE
THE TRANSIENT NATURE OF THE HIGHER WIND GUSTS.
RAIN WILL END FROM WEST TO EAST AFTER MIDNIGHT BUT THE WINDY
CONDITIONS WILL CONTINUE.
WINDY CONDITIONS WILL BE SEEN ACROSS THE AREA TUESDAY WITH CLOUDS
AND COOLER TEMPERATURES. IT IS POSSIBLE THAT THE DAYTIME HIGH 'MAY'
OCCUR DURING THE MORNING HOURS WITH STEADY OR SLOWLY FALLING
TEMPERATURES IN THE AFTERNOON.
THE BIGGEST IMPACT TUESDAY WILL BE THE WINDS. WINDS ARE EXPECTED TO
GUST UP TO 35 MPH AT TIMES WHICH MAY BLOW LOOSE OBJECTS AROUND AND
MAKE DRIVING DIFFICULT.
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/
ISSUED AT 219 PM CST MON NOV 18 2024
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT
ASSESSMENT...HIGH CONFIDENCE ON WINDY CONDITIONS AND TEMPERATURES
BELOW NORMAL. MEDIUM TO HIGH CONFIDENCE ON MIXED PRECIPITATION
OCCURRING.
WINDY BUT COLDER CONDITIONS WILL BE SEEN ACROSS THE AREA TUESDAY
NIGHT AND WEDNESDAY. WINDS MAY GUST UP TO 30 MPH AT TIMES.
ON WEDNESDAY, THE FIRST OF TWO CLIPPER-TYPE SYSTEMS WILL MOVE
THROUGH THE MIDWEST. THIS CLIPPER SYSTEM WILL ORIGINATE FROM THE
OCCLUDED SYSTEM LOW OVER SASKATCHEWAN/MANITOBA PROVINCES AND RACE
SOUTHEAST INTO THE OHIO VALLEY.
MOISTURE IS SOMEWHAT SPARSE AHEAD OF THE SYSTEM SO PRECIPITATION
AMOUNTS WILL BE QUITE LIGHT. GIVE THE COLDER AIR AT THE SURFACE AND
THE COLD CORE ALOFT ARRIVING, SHOWERS IN THE FORM OF A RAIN/SNOW MIX
OR PURE SNOW SHOWERS ARE VERY POSSIBLE. HOWEVER, THE GROUND IS STILL
EXTREMELY WARM (MID 40S TO MID 50S) SO GIVEN THE LIGHT NATURE OF THE
EXPECTED PRECIPITATION, ANY SNOW WOULD MELT ON CONTACT.
THURSDAY THROUGH SUNDAY
ASSESSMENT...HIGH CONFIDENCE ON BELOW NORMAL TEMPERATURES.
THE MODEL CONSENSUS HAS DRY CONDITIONS FOR THE LATE WEEK AND
WEEKEND. THE COMBINATION OF CYCLONIC FLOW AND THE COLD CORE ALOFT
TEMPERATURES WILL KEEP PLENTY OF CLOUDS AROUND THE AREA THURSDAY
THROUGH FRIDAY BEFORE SOME CLEARING IN THE FORM ON HIGH PRESSURE
OCCURS OVER THE WEEKEND.
ALTHOUGH THE MODEL CONSENSUS HAS DRY CONDITIONS, THE CYCLONIC FLOW
AND COLD TEMPERATURES ALOFT RAISES THE POSSIBILITY OF SOME ERRANT
SPRINKLES OR FLURRIES OCCURRING. THIS MAY GET BETTER REFINED OVER
THE NEXT COUPLE OF DAYS AS WE GET INTO THE TIME FRAME OF THE HIGHER
RESOLUTION MODELS.
THE BIGGER WEATHER IMPACT THURSDAY INTO FRIDAY LOOKS TO BE THE
CONTINUATION OF WINDY CONDITIONS. WINDS GUSTING UP TO 30 OR EVEN 35
MPH SHOULD BE COMMON ON THURSDAY WITH GUSTS TO 25 MPH ON FRIDAY.
SUNDAY NIGHT AND MONDAY
ASSESSMENT...MEDIUM CONFIDENCE REGARDING PRECIPITATION CHANCES
A CLIPPER-TYPE SYSTEM WILL MOVE THROUGH THE MIDWEST LATE SUNDAY
NIGHT INTO MONDAY. THE BETTER FORCING IS MINNESOTA INTO WISCONSIN
WHICH THUS HAVE THE BETTER PRECIPITATION CHANCES.
INTERESTINGLY, THE DETERMINISTIC GFS/ICON MODELS ARE THE FURTHEST
SOUTH WHILE THE ECMWF/CMC ARE MUCH FURTHER NORTH. THE ENSEMBLE
MEMBERS OF ALL MODELS HAVE A MAJORITY POINTING TO MN/WI FOR
PRECIPITATION WITH SUNDAY NIGHT DRY FOR THE IMMEDIATE AREA.
GIVEN THE DISCREPANCIES REGARDING TRACK, THE MODEL CONSENSUS HAS A
20% CHANCE OF PRECIPITATION LATE SUNDAY NIGHT AND MONDAY ALONG/EAST
OF THE MISSISSIPPI. PRECIPITATION TYPE LOOKS TO BE IN THE FORM OF
RAIN SHOWERS GIVEN THE WARMER TEMPERATURES.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1140 AM CST MON NOV 18 2024
WIDESPREAD LIFR/IFR CONDITIONS WILL PERSIST THROUGH 10Z/19
BEFORE CIGS SLOWLY RISE TO MVFR. LLWS WILL OCCUR ROUGHLY FROM
00Z-10Z/19 ACROSS EASTERN IOWA AND NORTHERN ILLINOIS WITH A
CONSIDERABLE WIND JUMP IN THE 1.2 TO 1.6 KFT AGL LAYER TO 50-55
KNOTS. TSRA POTENTIAL IS 10% OR LESS THROUGH 09Z/19 AND WAS NOT
INCLUDED IN THE 18Z TAFS. ANY SHRA OR ISOLATED TSRA WILL HAVE
THE POTENTIAL TO PRODUCE GUSTS TO 45 KNOTS DUE TO THE VERY
STRONG LOW LEVEL JET.
DVN WATCHES/WARNINGS/ADVISORIES
IA...NONE.
IL...NONE.
MO...NONE.
SHORT TERM...08
LONG TERM...08
AVIATION...08
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