091
FXUS63 KMKX 162031
AFDMKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MILWAUKEE/SULLIVAN WI
331 PM CDT WED OCT 16 2013
.SHORT TERM...
TONIGHT AND THURSDAY...FORECAST CONFIDENCE MEDIUM TO HIGH
THE AMPLIFIED UPPER LEVEL TROUGH MOVING THROUGH THE GREAT LAKES
REGION TODAY WILL SEPARATE THIS EVENING. THE SOUTHERN PORTION OF THE
TROUGH WILL SWING UP THROUGH THE GREAT LAKES AREA THURSDAY MORNING.
AS A RESULT...THE EXTENSIVE CLOUD SHIELD OVER WISCONSIN...IOWA AND
NORTHERN IL WILL HANG ON OVER SOUTHERN WI THROUGH AT LEAST THURSDAY
MORNING.
IF CLOUDS CAN CLEAR OVER THE NORTHERN MKX FORECAST AREA...TEMPS WILL
DROP INTO THE MID 30S...SO PATCHY FROST IS POSSIBLE THERE. NOT
ENOUGH CONFIDENCE IN THE CLOUDS CLEARING IN TIME TO HAVE A FROST
ADVISORY.
MOISTURE LOOKS DEEP ENOUGH TO SUPPORT LIGHT RAIN SHOWERS OVER
SOUTHEAST WI MAINLY THURSDAY MORNING AS THE LEADING VORT MAX WITH
THE UPPER LOW MOVES ACROSS. THERE IS UNCERTAINTY ABOUT THE NORTHERN
EXTENT OF THE SHOWERS...SO HIGHEST POP IN THE MKX AREA ARE 35
PERCENT FOR NOW. CLOUDS WILL KEEP TEMPERATURES LOWER IN SOUTHEAST
WI...AND SOME SUNSHINE BY THE AFTERNOON WILL ALLOW TEMPS TO GET UP
TO AROUND 60 IN PORTIONS OF SOUTH CENTRAL WI.
THURSDAY NIGHT THROUGH SATURDAY...FORECAST CONFIDENCE MEDIUM
A SHORTWAVE TROUGH WILL TRACK FROM MN THROUGH WI THU NT AND FRI
WITH A BROAD LOW PRESSURE AREA MOVING FROM NRN WI INTO ERN ONTARIO
CANADA. A COLD FRONTAL PASSAGE WITH WEAK FRONTOGENESIS WILL ENTER
THE FAR WRN CWA BY 12Z FRI AND MOVE TO LAKE MI BY LATE MORNING.
FCST SOUNDINGS DO SHOW SATURATION IN THE LOWER LEVELS BUT LITTLE
TO NO LIFT AND DRY IN THE MID TO UPPER LEVELS. THUS ONLY HAVE
SLIGHT CHANCE POPS IN THE FAR NRN CWA.
A DEEPER POLAR TROUGH WILL THEN DIG INTO THE UPPER MS RIVER VALLEY
AND NRN GREAT LAKES FOR FRI NT AND SAT. A BROAD SFC LOW OVER THE
NRN GREAT LAKES WILL RESULT WITH ANOTHER COLD FRONTAL PASSAGE OVER
SRN WI ON SAT. SOME FCST SOUNDINGS SHOW FAIRLY STEEP LAPSE RATES
AND SKINNY CAPE EXTENDING INTO THE MID LEVELS FOR SAT. INCREASED
POPS TO 50 PERCENT BUT MAY NEED TO BE HIGHER.
EXPECT COOL CONDITIONS FOR THIS PERIOD VIA A COUPLE COLD FRONTS
AND A POLAR TROUGH ALOFT...THEN SHOWERY ON SAT.
.LONG TERM...
SUNDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE LOW TO MEDIUM
WEAK HIGH PRESSURE AND COOL...PLEASANT CONDITIONS EXPECTED FOR
SUN. AFTERWARD...A STRONG...DIGGING SHORTWAVE TROUGH WILL MOVE
FROM CANADA INTO WI. CYCLOGENESIS IS EXPECTED OVER NRN WI AND
THROUGHOUT THE NRN GREAT LAKES INTO TUE AM. WHERE THE WARM
ADVECTION PCPN SETS UP WILL DEPEND ON HOW FAR NORTH THE
CYCLOGENESIS WILL OCCUR. PCPN WITH THIS SYSTEM WOULD BE MAINLY
SUN NT AND MON WITH COLD FROPA BY MON AFTERNOON AT THE LATEST.
MORE UNCERTAINTY AFTERWARD BUT WILL LIKELY SEE A BRIEF PERIOD OF
WEAK HIGH PRESSURE FOLLOWED BY A SHORTWAVE TROUGH WITHIN NW FLOW.
1000-500 MB THICKNESSES FOR NEXT WEEK WILL RANGE FROM 528-540 DM
AND DID MENTION SOME RAIN/SNOW MIX WITH LOW POPS FOR MON NT AND
TUE NT.
&&
.AVIATION/00Z TAFS/...
THE EXTENSIVE CLOUD SHIELD OVER WISCONSIN...IOWA AND NORTHERN IL
WILL HANG ON OVER SOUTHERN WI THROUGH AT LEAST THURSDAY MORNING.
PLAN ON THE MVFR CIGS TO PERSIST THROUGH THE NIGHT FOR MUCH OF
SOUTHERN WI. THERE COULD BE SOME CLEARING TOWARD CENTRAL WI LATE
TONIGHT.
ANOTHER WEAK LOW PRESSURE SYSTEM OVER THE PLAINS/MIDWEST WILL TRACK
ACROSS NORTHERN IL AND LAKE MICHIGAN ON THURSDAY...BRINGING A CHANCE
FOR SHOWERS TO SOUTHEAST WI MAINLY THURSDAY MORNING. MVFR CIGS WILL
BE LIKELY WITH THESE SHOWERS. THEN EXPECT CLOUDS TO RISE TO VFR AND
THIN/DIMINISH FROM WEST TO EAST THURSDAY AFTERNOON AND EVENING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/THURSDAY AND AVIATION/MARINE...MRC
THURSDAY NIGHT THROUGH WEDNESDAY...GEHRING