868
FXUS63 KGRB 250355
AFDGRB
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1055 PM CDT THU OCT 24 2024
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
KEY MESSAGES
- LIGHT RAINFALL IS EXPECTED TONIGHT INTO EARLY FRIDAY MORNING,
WITH MOST PLACES RECEIVING AMOUNTS OF 0.05 TO 0.15 INCH.
- NEAR TO ABOVE NORMAL TEMPERATURES EXPECTED INTO EARLY NEXT WEEK,
WITH NEAR RECORD HIGHS POSSIBLE ON TUESDAY.
- A MORE ACTIVE PATTERN IS EXPECTED DURING THE EARLY TO MIDDLE
PART OF NEXT WEEK WITH A FEW CHANCES FOR RAINFALL LATE MONDAY
THROUGH THURSDAY ALONG WITH BREEZY SOUTHERLY WINDS.
DISCUSSION
ISSUED AT 258 PM CDT THU OCT 24 2024
SHORT TERM...TONIGHT AND FRIDAY
PRECIPITATION TRENDS AND RAINFALL AMOUNTS WILL BE THE MAIN
FORECAST CONCERN, ALONG WITH THE RETURN OF COOLER TEMPERATURES.
DRY, MILD AND MOSTLY SUNNY CONDITIONS WERE OBSERVED ACROSS THE
FORECAST AREA THIS AFTERNOON, IN ADVANCE OF A COLD FRONT NEAR
THE DAKOTAS/MN BORDER. SHOWERS WERE DEVELOPING IN THE EASTERN
DAKOTAS AND MN, IN AN AREA OF 850-700 MB WAA AND UPPER DIVERGENCE
IN THE RRQ OF A JET STREAK. MID-LEVEL COUDS WERE THICKENING OVER
THE NORTHWEST HALF OF WI, BUT DRY AIR WAS PREVENTING ANY
PRECIPITATION FROM REACHING THE GROUND.
PRECIPITATION...HAVE SLOWED DOWN THE ARRIVAL OF PRECIPITATION A
LITTLE BIT THIS EVENING AND LOWERED POPS SLIGHTLY, AS MODELS
CONTINUE TO SHOW THE STRONGEST DYNAMICS SPLITTING NW AND SE OF THE
GRB FORECAST AREA TONIGHT. THE SOUTHERN AND WESTERN PARTS OF THE
AREA COULD STILL RECEIVE A TENTH OR TWO-TENTHS OF AN INCH OF
RAIN, BUT MUCH OF NE WI WILL SEE LESS THAN A TENTH OF AN INCH.
MID-LEVEL LAPSE RATES OF 6-6.5 C/KM SUGGEST POTENTIAL FOR A FEW
RUMBLES OF THUNDER OVER THE SOUTHERN THIRD OF THE AREA, BUT SINCE
MUCAPE VALUES ARE GENERALLY UNDER 100 J/KG, HAVE OPTED TO LEAVE
ANY MENTION OF STORMS OUT OF THE FORECAST. ANY LINGERING RAIN
SHOULD EXIT OUR LAKESHORE COUNTIES EARLY FRIDAY, FOLLOWED BY
CLEARING SKIES IN THE MID TO LATE MORNING.
TEMPERATURES/WINDS...GUSTY SOUTH WINDS WILL DIMINISH BY SUNSET,
BUT NORTHWEST WINDS WILL BECOME GUSTY AGAIN IN THE WAKE OF THE
COLD FRONT ON FRIDAY. LOWS TONIGHT WILL BE IN THE UPPER 30S AND
40S. CAA WILL RESULT IN COOLER HIGHS IN THE 50S AND LOWER 60S ON
FRIDAY.
LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
LOW-IMPACT WEATHER CONDITIONS ARE EXPECTED THROUGH THIS WEEKEND.
LONG RANGE ENSEMBLES DO SUPPORT A TRANSITIONS TO A MORE ACTIVE
PATTERN FOR THE EARLY TO MIDDLE PART OF NEXT WEEK.
THIS WEEKEND...A RIDGE OF HIGH PRESSURE IS EXPECTED TO DEVELOP OVER
THE WESTERN GREAT LAKES THIS WEEKEND KEEPING DRY CONDITIONS ACROSS
THE REGION. EXPECT NEAR NORMAL TEMPERATURES SATURDAY WITH A SLIGHT
WARMING TREND INTO SUNDAY AS 925MB TEMPERATURES WARM FROM 6-7C TO 10-
11C OVER THE NORTHERN HALF OF WI. WESTERLY WINDS SHOULD BE FAIRLY
LIGHT SATURDAY AND BECOME MORE BREEZY SUNDAY AS THEY BACK TO THE
SOUTHWEST AND THE SURFACE PRESSURE GRADIENT TIGHTENS.
NEXT WEEK...LREF ENSEMBLE MEMBERS ARE IN DECENT AGREEMENT THAT A
DEEP UPPER TROUGH WILL DEVELOP ACROSS THE INTER-MOUNTAIN WEST EARLY
NEXT. THERE IS A CHANCE (25-40%) FOR SCATTERED RAIN SHOWERS TO
DEVELOP OUT AHEAD OF THIS TROUGH WITH A SURGE OF WAA AND LEFT FRONT
JET QUAD MOVING OVER THE REGION MONDAY AFTERNOON INTO TUESDAY.
HOWEVER, THE HIGHER CHANCES FOR RAIN (50-60%) ARE FORECAST TO ARRIVE
WITH THE PASSAGE OF A COLD FRONT LATE WEDNESDAY INTO THURSDAY.
FORECAST SOUNDINGS DO SHOW SOME WEAK ELEVATED INSTABILITY AHEAD OF THE
COLD FRONT, SO A FEW RUMBLES OF THUNDER ARE NOT OUT OF THE QUESTION
AS THIS SYSTEM MOVES ACROSS THE REGION. IN ADDITION TO THE
PRECIPITATION CHANCES, SOUTHERLY WINDS ARE EXPECTED TO BE BREEZY
MONDAY THROUGH WEDNESDAY WITH GUSTS FORECAST TO REACH THE 20-30 MPH
AND A 15-20% FOR GUSTS GREATER THAN 40 MPH.
THE WAA AHEAD OF THE TROUGH WILL ALSO USHER IN VERY WARM TEMPERATURES
BY LATE OCTOBER STANDARDS WITH HIGHS ON TUESDAY FORECAST TO REACH
THE 70S AT MOST LOCATIONS. THERE IS A SLIGHT (LESS THAN 10%) THAT A
FEW LOCATIONS IN CENTRAL AND EAST-CENTRAL WI COULD REACH THE LOW
80S. TEMPERATURES BEHIND THE COLD FRONT ARE EXPECTED TO MODERATE BACK
TOWARD NORMAL FOR THE BACK HALF OF NEXT WEEK.
AVIATION
FOR 06Z TAF ISSUANCE
ISSUED AT 1055 PM CDT THU OCT 24 2024
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO TRACK THROUGH THE REGION
OVERNIGHT, AS A COLD FRONT AND ASSOCIATED UPPER LEVEL DISTURBANCES
MOVE THROUGH. SOME OF THE STRONGER SHOWERS AND STORMS COULD
CONTAIN GUSTY WINDS OF 20 TO 30 KNOTS. THE RAIN WILL TAPER OFF
FROM WEST TO EAST LATE TONIGHT INTO EARLY FRIDAY. A FEW
THUNDERSTORMS MAY FORM OVER THE SOUTHERN PART OF THE FORECAST AREA
IN THE LATE EVENING AND EARLY OVERNIGHT HOURS, BUT CONFIDENCE IS
TOO LOW TO MENTION IN THE TAFS. FLIGHT CONDITIONS SHOULD DROP TO
MVFR AT TIMES, ESPECIALLY OVER THE NW AND SE PORTIONS OF THE
FORECAST AREA, WHERE RAINFALL WILL PROBABLY BE MOST PERSISTENT.
THAT BEING SAID, OVERALL CONFIDENCE IN CEILING HEIGHTS IS LOW.
CONDITIONS WILL RETURN TO VFR FRIDAY MORNING BEHIND THE COLD FRONT
AS SKIES CLEAR OUT AND LAST INTO FRIDAY EVENING.
LIGHT SOUTH TO SOUTHWEST WINDS ARE EXPECTED TONIGHT, WITH
NORTHWEST WINDS DEVELOPING AS A COLD FRONT MOVES THROUGH LATER
TONIGHT INTO EARLY FRIDAY. WINDS WILL BECOME GUSTY BEHIND THE
FRONT LATER FRIDAY MORNING AND LASTING INTO THE AFTERNOON. AS
WINDS EASE FRIDAY EVENING AND LOW LEVEL WINDS INCREASE, LLWS WILL
DEVELOP AT THE TAF SITES.
MARINE
ISSUED AT 258 PM CDT THU OCT 24 2024
GIVEN A LACK OF GUSTS TO 25 KNOTS, AND WAVES ONLY
BRIEFLY TOUCHING 4 FT JUST EAST OF TWO RIVERS TONIGHT, HAVE OPTED
TO HOLD OFF ON ANY MARINE HEADLINES THROUGH FRIDAY NIGHT.
AN EXTENDED PERIOD OF GUSTY AND PERSISTENT SOUTH TO SOUTHWEST
WINDS AND HIGH WAVES WILL BRING HAZARDOUS BOATING CONDITIONS LATE
SUNDAY NIGHT THROUGH THE MIDDLE OF NEXT WEEK.
GRB WATCHES/WARNINGS/ADVISORIES
NONE.
DISCUSSION.....KIECKBUSCH/GK
AVIATION.......KURIMSKI
MARINE.........KIECKBUSCH
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