360
FXUS63 KMKX 161149
AFDMKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
649 AM CDT TUE JUL 16 2019
UPDATE
NO MAJOR CHANGES TO THE FORECAST THOUGH LOWER CLOUDS ARE SPREADING
INTO PARTS OF SOUTHERN WISCONSIN.
AVIATION(12Z TAFS)
IFR/MVFR CLOUDS ARE SPREADING INTO PARTS OF SOUTHERN WISCONSIN NOW
AND WILL CONTINUE TO PUSH EAST LIKELY IMPACTING PARTS OF SOUTHEAST
WISCONSIN FOR AT LEAST A PERIOD. AS THE AREA WARMS UP IT IS
EXPECTED FOR THE IFR CONDITIONS TO BECOME MOSTLY MVFR CONDITIONS
AND WITH CERTAIN AREAS BEING VERY THIN THE SUN MAY HELP TO REMOVE
THEM. THE MAIN CONCERN FOR LOW CIGS WILL BE IN THE FAR SOUTHEAST,
ESPECIALLY TOWARD KENOSHA AS LOW CLOUDS FROM THE REMNANTS OF BARRY
ENTER THE REGION. INTO THE AFTERNOON THIS SHOULD NO LONGER BE A
CONCERN WITH MVFR CIGS LIKELY OUT OF THE REGION. THE REST OF THE
DAY WILL BE VFR CONDITIONS WITH MOSTLY LIGHT SOUTHERLY WINDS.
CHANCE FOR A WEAK STORM/SHOWER TO THE WEST INTO THE EVENING BUT
THERE REMAINS QUITE A BIT OF UNCERTAINTY WITH PRECIPITATION
CHANCES.
PREV DISCUSSION
(ISSUED 415 AM CDT TUE JUL 16 2019)
SHORT TERM...
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM TO HIGH.
ANOTHER WARM DAY IS EXPECTED TODAY, THOUGH TEMPERATURES SHOULD BE
SLIGHTLY COOLER THAN MONDAY WITH WEAKER SOUTHWESTERLY FLOW FROM
THE WEAKENED PRESSURE GRADIENT. WE ALSO LOOK LIKE WE WILL REMAIN
MOSTLY DRY AGAIN, WITH SLIGHT CHANCES FOR SHOWERS TO THE
SOUTHEAST AND AGAIN IN THE NORTH/NORTHWEST/WEST.
THE BEST CHANCE FOR SHOWERS IN THE SOUTHEAST WILL BE THIS MORNING
AS REMNANTS OF BARRY COULD CLIP THE SOUTHEAST. THE BEST CHANCES
FOR SHOWERS/STORMS TO THE NORTHWEST WILL BE IN THE
EVENING/OVERNIGHT HOURS, AS AN UPPER LEVEL SHORTWAVE PULLS
THROUGH. THIS WILL BE SUPPORTED BY SOME LOW LEVEL WAA AND MOISTURE
ADVECTION, IN THE PRESENCE OF A LOW LEVEL BOUNDARY. THIS BOUNDARY
MAY CAUSE STORMS TO THE WEST THAT TRACK TOWARD THE REGION IN THE
EVENING. THERE REMAINS QUITE A BIT OF UNCERTAINTY WITH THIS, AS
THE MODELS SHOW DIFFERENT SOLUTIONS FOR WHERE STORMS WILL FORM AND
HOW THEY TRACK.
WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE IS MEDIUM.
MAIN ISSUE THIS PERIOD WILL BE THE HEAT AND POSSIBLE HEAT
HEADLINES FOR THURSDAY INTO SATURDAY.
GUSTY SOUTHWEST WINDS THURSDAY INTO FRIDAY WITH A FAIRLY TIGHT
PRESSURE GRADIENT SHOULD BRING VERY WARM TEMPERATURES INTO THE
AREA. 925 MB TEMPERATURES FROM THE MODELS, AND MODEL CERTAINTY
FORECASTS, SUGGEST LOWER TO MIDDLE 90S FOR THURSDAY, AND MIDDLE
90S, PERHAPS HIGHER WITH THE SOUTHWEST WINDS, FOR FRIDAY.
SATURDAY MAY SEE LOWER TO MIDDLE 90S AS WELL, THOUGH SOME
UNCERTAINTY HERE AS POSSIBLE THUNDERSTORMS AND CLOUDS MAY HOLD
DOWN HIGHS A BIT.
HEAT INDEX VALUES WILL BE SOLIDLY IN HEAT ADVISORY RANGE OF 100
TO 104 EACH DAY, WITH FRIDAY HIGHEST, IN THE 101 TO 107 RANGE.
THERE IS THE POSSIBILITY OF EXCESSIVE HEAT WATCHES/WARNINGS, GIVEN
THE POSSIBLE THURSDAY TO SATURDAY DURATION. STILL A LITTLE TIME
TO LET DAY SHIFT DECIDE WHAT HEAT HEADLINES WOULD BE THE MOST
APPROPRIATE FOR THIS PERIOD. WILL CONTINUE TO MESSAGE THIS
POTENTIAL IN PRODUCTS, WITH THE DAY SHIFT LIKELY TO MAKE A
DECISION ON HEAT HEADLINES FOR THURSDAY AND FRIDAY, PERHAPS INTO
SATURDAY.
OTHER ISSUE IS THUNDERSTORM CHANCES WEDNESDAY INTO SATURDAY.
WEAK CONFLUENCE/CONVERGENCE ACROSS THE AREA ON WEDNESDAY, ALONG
WITH A PASSING SHORTWAVE TROUGH, MAY BE ENOUGH TO BRING A FEW
THUNDERSTORMS. KEPT MAINLY LOWER END CHANCES FOR POPS WEDNESDAY,
HIGHEST IN THE NORTHERN COUNTIES. ANOTHER WARM AND HUMID DAY IS
EXPECTED, WITH UPPER 80S TO AROUND 90 EXPECTED INLAND WITH MIDDLE
90S HEAT INDEX VALUES. ONSHORE WINDS NEAR THE LAKE WILL KEEP
THINGS A LITTLE COOLER THERE.
MODELS RAMP UP LOW LEVEL JET FOR WEDNESDAY NIGHT, WITH THE NOSE OF
IT GRADUALLY SHIFTING FROM SOUTHERN MINNESOTA INTO CENTRAL
WISCONSIN IN THE EVENING, THEN FURTHER NORTHEAST OVERNIGHT. AN MCS
IS LIKELY TO DEVELOP TO THE WEST OF THE AREA BY EARLY WEDNESDAY
EVENING, THEN SHIFT EAST WITH THE LOW LEVEL JET NOSE OVERNIGHT.
THUS, THIS ACTIVITY MAY AFFECT PARTS OF THE AREA.
THE 4KM NAM NEST IS ACTUALLY BRINGING A RATHER STRONG MULTICELL
LINE SOUTHEAST THROUGH THE AREA LATER WEDNESDAY NIGHT INTO EARLY
THURSDAY MORNING. THERE ARE DECENT MID LEVEL LAPSE RATES, ELEVATED
CAPE AND DEEP LAYER BULK SHEAR, SO SOME STRONG/A FEW SEVERE
STORMS MAY BE POSSIBLE DURING THIS TIME. SPC MARGINAL RISK LOOKS
FINE FOR NOW ACROSS MOST OF THE AREA. WILL NEED TO SEE HOW LATER
CAMS HANDLE THIS POTENTIAL MCS.
THUNDERSTORM CHANCES LATER THURSDAY INTO THURSDAY NIGHT SEEM
MEAGER, AS THE BEST UPWARD VERTICAL MOTION WITH THE WARM FRONT
SHOULD BE NORTH/NORTHEAST OF THE AREA. KEPT SMALL POPS FOR NOW TO
BLEND WITH NEIGHBORS.
LONG TERM...
SATURDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE IS LOW.
THERE IS A FAIR AMOUNT OF UNCERTAINTY WITH TRENDS IN THIS PERIOD.
MODELS ARE TRYING TO SHOW SOME KIND OF COLD FRONT MOVING EAST
THROUGH THE REGION BETWEEN SATURDAY NIGHT INTO SUNDAY NIGHT. LEFT
MAINLY SMALL POPS IN THE FORECAST FOR THIS PERIOD, WITH CHANGES TO
COME AS WE GET CLOSER TO THIS PERIOD. IT DOES LOOK LIKE WE WILL
COOL OFF TO MORE SEASONABLE TEMPERATURES BEHIND THE COLD FRONT,
WHENEVER THAT DOES MOVE THROUGH THE AREA.
AVIATION(09Z TAF UPDATES)...
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD, AS ANY LOW
CLOUDS IN THE REGION LATER THIS MORNING WILL LIKELY BE SCATTERED.
WHILE THE REMNANTS OF BARRY THAT IS PUSHING NORTH MAY HAVE SOME
MVFR CLOUDS, IT IS EXPECTED THAT THESE LOWER CLOUDS WILL REMAIN TO
OUR SOUTHEAST. OTHERWISE, THERE IS A SLIGHT CHANCE FOR A SHOWER
IN THE SOUTHEAST AS A RESULT OF BARRY.
INTO THE EVENING AND OVERNIGHT WE WILL SEE CHANCES SHOWERS/STORMS,
WHICH COULD CAUSE SOME MINOR VSBY CONCERNS, AS WELL AS SOME MVFR
CLOUDS. HOWEVER, THERE IS STILL QUITE A BIT OF UNCERTAINTY, AS
MUCH OF THE REGION IS EXPECTED TO REMAIN DRY, WITH THE POTENTIAL
FOR MVFR CLOUDS DURING THIS TIME BEING THE BIGGEST CONCERN.
MARINE...
SOUTHWESTERLY WINDS WILL REMAIN BREEZY ACROSS THE NORTHERN HALF
OF THE LAKE TODAY, BUT WILL SLOWLY DECREASE AS THE LOW PRESSURE
SYSTEM MOVES FURTHER AWAY. THOUGH WINDS WILL WEAKEN, WE EXPECT
THEM TO REMAIN LIGHT FROM THE SOUTH THROUGH WEDNESDAY. THE BREEZY
SOUTH/SOUTHWEST WINDS WILL THEN RETURN FOR LATE WEDNESDAY NIGHT
AND THURSDAY, AS LOW PRESSURE APPROACHES FROM THE WEST.
MKX WATCHES/WARNINGS/ADVISORIES
WI...NONE.
LM...NONE.
UPDATE...ARK
TODAY/TONIGHT AND AVIATION/MARINE...ARK
WEDNESDAY THROUGH MONDAY...WOOD
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