316 PM CDT
REST OF TODAY...PRECIPITATION WILL CONTINUE TO SINK SOUTHEAST ALONG
WITH THE DEPARTING LOW AND WEAKENING AREA OF FRONTOGENESIS.
ANTICYCLONIC FLOW AND DRY AIR/SUBSIDENCE ARE EVIDENT ON WV
IMAGERY...AND QUICKLY DROPPING SOUTH ACROSS WISCONSIN TOWARD THE
CWA. THIS WILL ALLOW SKIES TO CLEAR FROM THE NORTHWEST BEGINNING
THIS EVENING.
TONIGHT...RIDGE AXIS CONTINUES TO SINK SOUTH AND STRONG SURFACE
DECOUPLING IN RESPONSE TO RADIATIONAL COOLING WILL DEVELOP...
ESPECIALLY ACROSS THE NORTH/WEST PORTIONS OF THE CWA...AND WILL SET
THE STAGE FOR FOG DEVELOPMENT OVERNIGHT. SOME AREAS RECEIVED OVER AN
INCH OF PRECIPITATION OVER THE PAST 24 HRS...WHICH WILL KEEP SURFACE
MOISTURE CONTENT HIGH. TEMPERATURES ARE EXPECTED TO DROP INTO THE
UPPER 20S TO AROUND 30 WEST OF THE FOX RIVER VALLEY...WITH LOW TO
MID 30S ELSEWHERE. MAY SEE SOME AREAS ACROSS THE NORTHWEST PORTION
OF THE CWA WAKE UP TO SOME LIGHT ICE ACCUMULATIONS ON ELEVATED
SURFACES DUE TO FREEZING FOG...BUT OTHERWISE MAIN FOG CONCERN WILL
BE POTENTIAL FOR DEVELOPMENT OF DENSE FOG. MET/MAV MOS GUIDANCE IS
NOT REALLY SUPPORTING THE IDEA YET...BUT OVERALL ENVIRONMENT AS
DISCUSSED SEEMS VERY SUPPORTIVE. TEMPERATURES ALONG THE LAKE FRONT
WILL LIKELY STAY TOO WARM TO WORRY ABOUT THIS OVER THE METRO AREA
//IN ADDITION TO TYPICAL URBAN HEAT ISLAND//...AND SOUTH/EAST
PORTIONS OF THE CWA WILL SEE CLOUD COVER HANG ON A LITTLE LONGER AND
LIKELY SOME ELEVATED WINDS.
FRIDAY THROUGH SUNDAY...FEW CONCERNS FOR THE END OF THE WORK WEEK
THROUGH THE WEEKEND. SURFACE RIDGE AXIS SLIDES EAST THROUGH THE AREA
DURING THIS PERIOD AND STRONG UPPER RIDGE BUILDS OVERHEAD. WINDS
WILL GRADUALLY STRENGTHEN OVER THE WEEKEND AS OUR NEXT AREA OF LOW
PRESSURE DEVELOPS OVER THE CENTRAL PLAINS AND QUICKLY MOVES NNE
ACROSS THE NORTHERN PLAINS. TEMPERATURES WILL WARM NICELY IN
RESPONSE TO THE WARM ADVECTION...WITH MAX TEMPS UPPER 50S TO LOW 60S
FOR SATURDAY AND SUNDAY.
NEXT WEEK...ANOTHER AREA OF LOW PRESSURE DEEPENS OVER THE CENTRAL
PLAINS IN RESPONSE TO POTENT TROUGH DIGGING ACROSS THE INTERMOUNTAIN
WEST. STRONG LOW LEVEL JET DEVELOPS OUT AHEAD OF THE LOW ADVECTING
HIGH THETA-E AIR NORTH ACROSS THE CWA ON TUESDAY. THE LOW CENTER IS
FORECAST TO TRACK NORTHEAST ACROSS THE MID MISSOURI VALLEY...WITH
SLIGHT DISCREPANCIES IN THE TRACK BETWEEN THE GFS AND ECMWF.
UNFORTUNATELY THIS HAS SOME IMPACTS ON THE PRECIP AND TEMPERATURE
FORECAST FOR TUESDAY...WITH THE ECMFW HAVING SIGNIFICANTLY WARMER
TEMPERATURES...AROUND 10 DEGREES FOR SOME AREAS. OPTED TO BUMP UP
TEMPERATURES ACROSS SOUTHEAST WHICH WERE MOST LIKELY TO BE WELL INTO
THE WARM SECTOR BY THEN...BUT MAY HAVE TO COME UP MORE IF THESE
TRENDS HOLD. WILL ALSO HAVE TO MONITOR CONVECTIVE THREAT FOR
TUESDAY...AND SHOULD CURRENT ECMWF TRACK...OR A MORE WESTERN TRACK
TO THE LOW PAN OUT...MAY END UP SEEING SOME NON-ZERO SEVERE THREAT
THANKS TO VERY STRONG BULK SHEAR VALUES...THOUGH MAIN PROHIBITIVE
FACTOR PERHAPS MAY BE LACK OF ANY INSTABILITY...AND THE THREAT MAY
STAY FARTHER SOUTH. THIS FAR OUT...NOT WORTH MORE THAN THIS SHORT
MENTION IN THE AFD. THE LOW WILL LIFT NORTHEAST OF THE AREA ON
WEDNESDAY...WITH SOME LINGERING WRAP AROUND MOISTURE POSSIBLE.
SEVERAL THICKNESS THRESHOLDS INCLUDING THE 540 LINE DROP WELL SOUTH
OF THE CWA IN RESPONSE TO THE COLD ADVECTION...AND CANT RULE OUT ANY
PRECIPITATION POSSIBLY CHANGING OVER TO SNOW FOR A PERIOD LATE
WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING. UPPER LEVEL RIDGING
BEGINS TO BUILD BACK ACROSS THE REGION THURSDAY HOWEVER...ALLOWING
TEMPS TO WARM BACK UP. BMD
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* GUSTY NORTHEAST WINDS DIMINISHING AROUND OR SHORTLY AFTER 00Z.
* MVFR CEILINGS IMPROVING THROUGH THE EVENING.
* RAIN ENDING AT MDW BY 23-00Z.
KREIN
//DISCUSSION...UPDATED 18Z...
LOW PRESSURE SYSTEM CENTERED OVER SOUTHERN IL WILL CONTINUE MOVING
TO THE EAST. THE TERMINALS HAVE BEEN ON THE NORTHERN FRINGE OF A
LARGE AREA OF PRECIPITATION ASSOCIATED WITH THE LOW...WHICH WILL
ALSO MOVE AWAY TO THE EAST. HIGH PRESSURE WILL BE BUILDING INTO
THE AREA FROM THE WEST TONIGHT. THIS WILL ALLOW WINDS TO DIMINISH
RAPIDLY THIS EVENING AND CEILINGS TO CLEAR OUT. A CLASSIC SET UP
FOR FOG TO DEVELOP TOWARDS DAYBREAK ON FRIDAY...ESPECIALLY AT RFD
AND DPA.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH CONFIDENCE IN CEILING AND PRECIPITATION TREND.
* MEDIUM CONFIDENCE WIND GUST ENDING TIME.
* HIGH CONFIDENCE IN ALL OTHER ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...VFR.
SUNDAY...SLIGHT CHANCE OF SHRA LATE...OTHERWISE VFR.
MONDAY...SLIGHT CHANCE OF SHRA...OTHERWISE VFR.
TUESDAY...SHRA LIKELY...OTHERWISE VFR.
WEDNESDAY...CHANCE OF SHRA...OTHERWISE VFR.
RODRIGUEZ
&&
.MARINE...
225 PM CDT
AS THE LOW PRESSURE OVER SOUTHERN IL MIGRATES EAST...THE PRESSURE
GRADIENT WILL GRADUALLY RELAX OVER SOUTHERN LAKE MI TONIGHT. THIS
WILL ALLOW FOR NORTHEAST WINDS TO FALL SLOWLY AWAY FROM GALE
CRITERIA. WIND SPEED OBSERVATIONS NEAR THE SURFACE ARE ALSO
TRENDING DOWN...MANY JUST BELOW 30 KTS AS OF 215 PM. GUSTS
OF 25 TO 30 KTS WILL REMAIN POSSIBLE THROUGH THE EVENING HOURS.
WAVE HEIGHTS WILL ACCORDINGLY FALL TONIGHT...WITH THE HIGHEST
HEIGHTS SEEN BETWEEN THE SOUTH BUOY AND CHICAGO GIVEN THE LONG
DURATION NORTHEAST WIND DIRECTION. GIVEN THE HIGHER WINDS IN THE
IL AND IN NEAR SHORE AREAS...HAVE ISSUED A SMALL CRAFT ADVISORY TO
FOLLOW THE GALE WARNING. THIS WILL BE IN EFFECT INTO FRIDAY
MORNING WITH THE SLOWLY SUBSIDING WAVES. THE HIGH PRESSURE RIDGE
WILL MOVE OVER THE AREA QUICKLY DURING FRIDAY OFFERING A BRIEF
RESPITE...BEFORE SOUTHERLY FLOW AND A TIGHTENED PRESSURE GRADIENT
ONCE AGAIN BUILDS OVER LAKE MI. THIS LOOKS TO SUPPORT GALE
CONDITIONS...POTENTIALLY AS EARLY AS SATURDAY AFTERNOON...BUT MOST
FAVORED SATURDAY NIGHT INTO SUNDAY.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 AM FRIDAY.
&&
$$
