335 AM CDT
A NEGATIVELY TILTED UPPER TROUGH CONTINUES TO ROTATE
NORTHEASTWARD OVER THE UPPER GREAT LAKES EARLY THIS MORNING
AS A STRONG JET MAX PUNCHES SOUTHEAST ACROSS THE DAKOTAS TO THE
LOWER OH VALLEY. THE RAIN ASSOCIATED WITH THE UPPER TROUGH HAD
SHIFTED NORTHEAST AND EAST OF THE LOCAL FORECAST AREA LATE LAST
EVENING WITH RAPID CLEARING OF ANY CLOUDS FOLLOWING THE PASSAGE
OF THE SHARP TROUGH AXIS.
LAST FEW FRAMES OF WATER VAPOR AND IR SATELLITE LOOPS SHOW THE
BEGINNINGS OF THE UPPER LOW FORMATION OVER CENTRAL LAKE MI AS
DEPICTED BY THE MODELS. SLOWING OF THE EASTWARD PROGRESS OF THE
SYSTEM ANTICIPATED AS THE UPPER LOW FULLY FORMS AND HANDLED WELL
BY THE MODELS MOVING OVER THE CENTRAL AND EASTERN GREAT LAKES
LATER TODAY AND TONIGHT. SIGNIFICANT COOLING OF MID AND UPPER
LEVELS HAS BEEN OCCURRING FOLLOWING THE UPPER TROUGH PASSAGE LATE
THU EVENING. WITH SURFACE HEATING AND RESIDUAL LOW LEVEL MOISTURE
EXPECT TO SEE BROKEN CLOUD COVER BY LATER MORNING AND THROUGH THE
AFTERNOON AS DIURNAL STRATOCU SPREADS AIDED BY THE SMALL MID LEVEL
DISTURBANCE APPROACHING FROM SOUTHEAST MN.
ALONG WITH CLOUD FORMATION...HEATING WILL DEEPEN THE MIXED LAYER
UP TO AROUND 1.5KM AGL WHERE WEST-NORTHWEST WINDS OF 35-40KT ARE
FORECAST BY THE MODELS. MOMENTUM TRANSFER DOWN TO THE SURFACE
WILL BEGIN AROUND MID MORNING AS SURFACE TEMPERATURES WARM BACK
UP INTO THE MID 50S. BUFKIT SHOWS 30-35KT TRANSFER DOWN TO NEAR
GROUND LEVEL LATER TODAY. WINDS MAY OCCASIONALLY MEET OR EXCEED
ADVISORY CRITERIA OF 26KT SUSTAINED AND/OR GUSTS OF 39 KT BUT IT
APPEARS THAT PREVAILING CONDITIONS WILL REMAIN JUST BELOW THE
THRESHOLD.
NEXT THREAT OF PRECIPITATION ARRIVES LATER SAT NIGHT AND SUN AS
A SHORT WAVE CURRENTLY OVER NORTHERN B.C. DROPS SOUTHEAST ACROSS
THE DAKOTAS AND THE UPPER MS VALLEY...REACHING THE WESTERN GREAT
LAKES BY SUN EVENING. WITH THE SHORT WAVE TURNING EASTWARD AS IT
APPROACHES THE SOUTH SIDE OF THE UPPER LOW THAT TAKES UP
RESIDENCE OVER SOUTHERN HUDSON BAY THE THREAT OF RAIN WILL BEGIN
DROPPING OFF FOR SUN AFTERNOON.
RAIN CHANCES INCREASE AGAIN MON AS THE STRONG SHORT WAVE OVER THE
EASTERN ALEUTIAN PENINSULA CROSSES THE NORTHERN ROCKIES SUN NIGHT
AND CONTINUES OUT OVER THE CENTRAL PLAINS DURING MON. THIS SHORT
WAVE IS PROGGED TO CONTINUE TO DIG SOUTHEASTWARD MON NIGHT AND
TUE WHICH WOULD SUGGEST MOST PRECIPITATION WOULD OCCUR OVER
CENTRAL IL AND POINTS SOUTH BUT GIVEN THE FORECAST STRENGTH OF
THE SYSTEM AND THE ASSOCIATED WARM AIR ADVECTION PATTERN INTO
EAST CENTRAL AND NORTHEAST IL AS WELL AS NORTHWEST IND BY MON
MIGHT EXPECT THE ENTIRE LOCAL FORECAST AREA TO HAVE AT LEAST A
CHANCE OF RAIN.
ON THE BACK SIDE OF THIS SYSTEM IS EQUALLY STRONG COLD AIR
ADVECTION WITH 850HPA TEMPERATURES FALLING TO AROUND -2C OVER THE
AREA BY 00Z WED. STRONG NORTH WINDS DOWN THE RELATIVELY WARM LAKE
WATERS APPEARS TO BE A GOOD SETUP FOR LAKE EFFECT RAIN SHOWERS
ALONG THE IMMEDIATE IL SHORES AND ON INTO NORTHWEST IND FOR TUE
NIGHT. THESE SHOULD SHIFT EASTWARD WITH TIME AS THE LOW LEVEL FLOW
GRADUALLY BACKS.
TEMPERATURES TO BE IN NORMAL RAGE FOR MID OCT THROUGH THE WEEKEND
AND INTO EARLY NEXT WEEK BUT AS THE STRONG SHORT WAVES MOVES
ACROSS THE MID MS VALLEY LATE MON NIGHT AND TUE MORNING THE COLD
AIR THAT HAS BEEN KEPT FAR NORTH OVER NORTHERN CANADA WILL BE
SPILLING SOUTHWARD FOR MID NEXT WEEK WHEN HIGHS WILL BE LIMITED TO
THE LOWER AND MID 50S WITH OVERNIGHT LOWS FROM MID 30S TO MID 40S.
TRS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* WLY WINDS GUSTING TO ARND 25KT BY LATE MORNING...INCREASING TO
ARND 35KT DURG THE AFTERNOON.
KREIN
//DISCUSSION...UPDATED 12Z...
WITH STRONG COLD ADVECTION ON THE BACK SIDE OF THE EXITING LOW
PRESSURE SYSTEM...THE MAIN FORECAST CONCERN FOR TODAY WILL BE
WINDS. WIND DIRECTION WILL REMAIN GENERALLY WESTERLY THOUGH THE
PERIOD. BY LATE THIS MORNING...AMPLE SUNSHINE WILL ALLOW STRONGER
WINDS ALOFT TO MIX DOWN TO THE SFC. GUSTS TO ARND 25KT ARE LIKELY
BY 14-15Z. GUSTS WILL STRENGTHEN THROUGH THE DAY...REACHING ARND
35KT...OR POSSIBLY AS HIGH AS 40KT...DURG THE AFTERNOON HOURS.
GUSTINESS WILL DECREASE AFTER SUNSET...BUT WINDS WILL REMAIN
FAIRLY BRISK OVERNIGHT AT 10-15KT. SOME MID AND HIGH CLOUD SHOULD
MOVE OVER THE REGION TODAY...BUT NO OPERATIONALLY SIGNIFICANT
CLOUD COVER IS EXPECTED.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM TO HIGH CONFIDENCE IN TIMING AND STRENGTH OF WIND GUSTS
TODAY.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 12Z SATURDAY-12Z THURSDAY...UPDATED 00Z...
SATURDAY...VFR WITH GUSTY W WINDS.
SUNDAY THROUGH TUESDAY...VFR WITH PERIODIC RAIN CHANCES...SOME
MVFR POSSIBLE.
WEDNESDAY...VFR.
JEE
&&
.MARINE...
334 AM CDT
AN ELONGATED AREA OF LOW PRESSURE MOVED ACROSS LAKE MICHIGAN LAST
EVENING AND IS HEADING INTO LAKE HURON TODAY. AS IT DOES SO IT WILL
CONSOLIDATE AND DEEPEN RAPIDLY...SUPPORTING A QUICK INCREASE IN
WINDS ACROSS THE AREA. VERY EARLY THIS MORNING...HIGHER PLATFORMS
ON THE MICHIGAN SIDE OF THE LAKE ARE ALREADY GUSTING INTO THE LOWER
30S...WHILE EVEN THE SOUTH BUOY IS GUSTING TO 29 KT. THUS HAVE
MAINTAINED THE PREVIOUS START TIMES FOR THE GALE HEADLINES OVER THE
OPEN WATERS...AND COORDINATED WITH SURROUNDING OFFICES TO GO WITH AN
EARLIER START TIME FOR THE NEARSHORE GALES.
WIND SPEEDS AND DIRECTIONS WILL SEE LITTLE VARIATION THROUGH THE
NEXT 48 HOURS OR SO UNTIL THE LOW PULLS FARTHER AWAY TO THE NORTH.
THERE MAY BE A PERIOD TOMORROW NIGHT WHERE LOWER WIND SPEEDS OVER
THE LAND BLEED INTO THE NEARSHORE WATERS AND BRIEFLY DROP WINDS
BELOW GALE CRITERIA...BUT THIS WOULD NOT WARRANT A BREAK IN THE
HEADLINES. BY SUNDAY HIGH PRESSURE MOVES INTO THE SOUTHERN PART OF
THE LAKE...BUT THE STILL DEEPENING LOW WILL CONTINUE TO MAKE ITS
PRESENCE FELT ACROSS THE NORTHERN END OF THE LAKE EVEN AS IT SPINS
OVER JAMES BAY.
EML
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 AM FRIDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...10 AM
FRIDAY TO 1 PM SATURDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868 UNTIL 1 AM SUNDAY.
GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 1 AM SUNDAY.
&&
$$
