749 PM CDT
FRESHENED UP SHORT TERM GRIDS A BIT TO REFLECT ONGOING TRENDS.
SHARP CLEARING LINE IN THE WAKE OF THE FRONT/TROUGH AXIS CONTINUES
AND SHIFT EASTWARD WITH SKIES GOING CLEAR IN ITS WAKE. THERE IS AN
AREA OF ALTOSTRATUS OVER WESTERN WISCONSIN TH AT IS ROTATING
SOUTHEASTWARD TOWARD NORTHERN ILLINOIS...HOWEVER SATELLITE IMAGERY
DOES INDICATE THAT THIS AREA OF CLOUDINESS IS DIMINISHING. HAVE
ALSO SEEN A DECREASE IN THE CUMULUS FIELD UPSTREAM OVER
IOWA...THOUGH SOME ALTOCUMULUS REMAINS AND IF IT HOLDS TOGETHER
COULD PROVIDE FOR A FEW CLOUDS OVERNIGHT.
HAVE GOTTEN REPORTS OF PATCHY GROUND FOG DEVELOPING IN A NORTH-
SOUTH REGION BEHIND THE BACK EDGE OF THE RAIN PRIOR TO THE DRIER
AIR ADVECTING IN. SURFACE OBS SUGGEST THAT DRIER AIR WILL FILTER
IN AND THAT ALONG WITH SOME WIND SHOULD KEEP FOG FROM BECOMING A
PROBLEM OVERNIGHT.
AS AXIS OF STRONGER PRESSURE RISES SHIFTS EASTWARD WILL LIKELY SEE
WINDS RAMP UP A BIT THIS EVEN FROM THE NW. MUCH STRONGER WINDS ARE
EXPECTED DURING THE DAY FRIDAY WITH BUFKIT SOUNDINGS SUGGESTING
THE BOUNDARY LAYER COULD MIX INTO THE 40-45KT WINDS AT
850MB...WHICH SHOULD RESULT IN FREQUENT GUSTS OF 30-40 MPH AND
PROBABLY A FEW GUSTS OVER 40 MPH FRIDAY. GENERALLY LOOKS LIKE WE
WILL STAY BELOW ADVISORY CRITERIA...BUT STILL A VERY WINDY DAY.
IZZI
//PREV DISCUSSION...
342 PM CDT
MAIN FORECAST CONCERNS ARE WITH PRECIP TRENDS LATE THIS AFTERNOON
INTO THE EVENING...BEFORE THIS MAIN AREA OF PRECIPITATION FINALLY
SHIFTS OUT OF THE AREA LATER TONIGHT.
LATEST RADAR IMAGERY SHOWING A LARGE AREA OF PRECIP EXTENDING
ACROSS MUCH OF THE CWA LATE THIS AFTERNOON...WHICH HAS BEEN THE
CASE FOR MUCH OF THE DAY. THIS IS ONGOING AS THE CURRENT LONGWAVE
TROUGH CONTINUES TO EXTEND ACROSS THE ENTIRE REGION WITH SEVERAL
EMBEDDED WAVES OF ENERGY ROUNDING THE BASE. WITH THIS IN
PLACE...LATEST SATELLITE IMAGERY DEPICTING A STRONG/SHARPER SHORT
WAVE TROUGH CONTINUING TO PUSH EAST ACROSS THE MIDWEST. WITH THIS
TROUGH SHIFTING EAST THROUGH THE LARGER SCALE TROUGH...A
SHEAR/DEFORMATION ZONE HAS DEVELOPED AND HELPED TO MAINTAIN
STRONGER AREAS OF SHOWERS OVER NORTHEAST ILLINOIS. THIS LARGER
AREA OF MORE MODERATE RAINFALL HAS NOW SHIFTED EAST/NORTHEAST OVER
THE LAKE AND NORTHWEST INDIANA...AND WILL CONTINUE THIS MOVEMENT
INTO THE EVENING. AS THIS HAS OCCURRED TODAY...SOME DRIER ALOFT
MOVED THROUGH NORTHERN ILLINOIS INITIALLY DRYING CONDITIONS ACROSS
THE FAR WESTERN CWA. ALTHOUGH SINCE THEN...THIS DRIER HAS HELPED
THIS AREA BECOME MORE CONVECTIVELY UNSTABLE. THIS COINCIDING WITH
STEEPENING LOW LEVEL LAPSE RATES IN TURN HELPED WITH THE
DEVELOPMENT OF SHOWERS ACROSS THIS AREA THIS PAST AFTERNOON...WITH
LATEST RADAR IMAGERY SHOWING THESE MORE CONVECTIVE ELEMENTS
SHIFTING EAST THROUGH NORTH CENTRAL ILLINOIS. ALTHOUGH WE HAVE
BECOME MORE UNSTABLE...WITH VERY LITTLE INSTABILITY TO STILL WORK
WITH...THUNDER HAS BEEN NONEXISTENT AND FEEL THAT THIS WILL
CONTINUE AS CONDITIONS BECOME LESS FAVORABLE LATER THIS EVENING.
EXPECT THIS PRECIP TO CONTINUE TO SHIFT EAST THROUGH THE REMAINDER
OF THE AFTERNOON AND EARLY EVENING BEFORE A GRADUAL DRYING TREND
BEGINS TO OCCUR. THIS WILL OCCUR AS MAIN AXIS OF
PRECIPITATION...DUE TO LARGE/SYNOPTIC SCALE FORCING...SHIFTS EAST
OUT OF THE REGION AND CONDITIONS BECOME LESS FAVORABLE DIURNALLY.
WITH PRECIP ENDING FROM WEST TO EAST AND CLOUD COVER SHIFTING
EAST...SKIES WILL CLEAR THIS EVENING. ALTHOUGH LOOKING UPSTREAM
ACROSS THE PLAINS...ADDITIONAL WAVES OF ENERGY CAN BE OBSERVED
DROPPING SOUTH/SOUTHEAST WITH ASSOCIATED MID AND HIGH LEVEL CLOUD
COVER. DISTANCE SPEED TOOL AND LATEST SHORT RANGE GUIDANCE
INDICATE THAT THESE MID LEVEL FEATURES WILL SHIFT THROUGH THE
REGION TONIGHT. DONT FEEL THERE IS ANY THREAT OF ADDITIONAL
SHOWERS...BUT THERE COULD BE SOME ADDITIONAL CLOUD COVER WHICH
COULD SPILL OVER THE ALREADY CLEARING SKIES.
AS THIS UPPER LEVEL TROUGH CONTINUES TO DIG SOUTHEAST ACROSS THE
REGION ON FRIDAY...IT WILL BEGIN TO CLOSE ITSELF OFF AND STICK
AROUND THE AREA INTO THE START OF THE WEEKEND. THIS WILL HELP TO
MAINTAIN CYCLONIC FLOW ACROSS THE AREA AND A STREAM OF COOLER
AIR...WHICH WILL HELP WITH STRATOCU DEVELOPMENT ON FRIDAY AND
COOLER HIGH TEMPS. ALTHOUGH I HAVE REMOVED ANY MENTION OF SHOWERS
FOR FRIDAY...THATS NOT TO SAY A FEW SPRINKLES MIGHT BE OBSERVED AS
LOW LEVEL LAPSE RATES STEEPEN ONCE AGAIN.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 02Z...
* BRIEF W TO NW GUSTS UP TO 20 KT ARE POSSIBLE FOR THE NEXT HOUR.
* CIGS MAY BRIEFLY DROP TO MVFR OVER THE NEXT HOUR AS AN AREA OF
DISSIPATING MVFR CLOUDS PASSES THROUGH THE TERMINALS.
* GUSTY W TO NW WINDS RETURN TOMORROW MORNING.
JEE
//DISCUSSION...UPDATED 00Z...
THE SURFACE LOW HAS PUSHED OFF TO THE NORTHEAST...AND THE COLD FRONT
HAS PASSED THROUGH THE TERMINALS AS WELL. ONLY GYY WILL BE AFFECTED
BY THE LINE OF -SHRA FOR THE NEXT HOUR...AS THE LINE OF -SHRA IS
EAST OF THE OTHER TERMINALS. CONDITIONS WILL BEGIN TO IMPROVE
SIGNIFICANTLY OVER THE NEXT FEW HOURS. SKIES WILL BECOME VFR FROM
WEST TO EAST...WITH ALL TERMINALS AT VFR BY 01Z. KEPT FEW100...BUT
SKIES MAY BECOME SKC OVERNIGHT TONIGHT. BRIEF GUSTY WINDS MAY OCCUR
THIS EVENING AS THE SURFACE BECOMES DECOUPLED. EXPECTING W TO NW
WINDS UP TO 11KT TO CONTINUE OVERNIGHT. W TO NW GUSTS RETURN BY
14Z...OR A SMIDGE EARLIER AS THE SURFACE COUPLES WITH THE STRONGER
MID LEVEL FLOW. THE STRONG W TO NW FLOW IS BEING CAUSED BY THE LOW
DEEPENING TO OUR NE. TOMORROW AFTERNOON GUSTS UP TO 32 KT ARE
LIKELY...WITH HIGHER GUSTS POSSIBLE. INDICATED THAT GUSTS WILL
DIMINISH BY 15/01Z IN THE ORD TAF...BUT THAT TIME MAY BE OPTIMISTIC
DEPENDING ON WHEN THE SURFACE DECOUPLES FROM THE UPPER ATMOSPHERE.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 02Z...
* HIGH CONFIDENCE IN CIG HEIGHTS AND TRENDS.
* MEDIUM CONFIDENCE IN TIMING AND STRENGTH OF WIND GUSTS TOMORROW.
JEE
//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...
245 PM CDT
PERIOD OF WEST TO NORTHWEST GALES ARE EXPECTED ACROSS LAKE MICHIGAN
FROM LATER TONIGHT THROUGH MUCH OF SATURDAY AS LOW PRESSURE
CURRENTLY OVER WISCONSIN AND FAR SOUTHERN LAKE MICHIGAN DEEPENS
SIGNIFICANTLY WHILE LIFTING NORTHEAST TO NEAR JAMES BAY. FORECAST
SOUNDINGS FROM VARIOUS NUMERICAL MODELS INDICATE FREQUENT GUSTS
RISING INTO THE 40-45 KT RANGE DURING THE PERIOD...BEFORE GRADUALLY
TAILING OFF LATE SATURDAY/SATURDAY NIGHT AS THE LOW PULLS FARTHER
AWAY.
BASED ON THIS HAVE ELECTED TO HOIST GALE WARNINGS FOR THE OPEN
WATERS...BEGINNING LATE TONIGHT ON THE SOUTH HALF...AND EARLY FRIDAY
MORNING FARTHER NORTH AS WINDS ARE EXPECTED TO INCREASE FROM SOUTH
TO NORTH FOLLOWING THE TRACK OF THE LOW.
HEADLINES IN THE IL/IN NEARSHORE WATERS OF SOUTHERN LAKE MICHIGAN A
LITTLE TRICKIER...WITH WINDS INCREASING ENOUGH FOR SMALL CRAFT
ADVISORY CONDITIONS PRIOR TO THE START OF GALE FORCE WINDS TONIGHT.
THUS WILL HAVE AN SCA FOR THE NEARSHORE ZONES BEGINNING AT 06Z
TONIGHT...WITH GALES DEVELOPING MIDDAY FRIDAY.
CONDITIONS WILL STEADILY IMPROVE SATURDAY NIGHT INTO SUNDAY AS THE
LOW PULLS AWAY...AND WEAK HIGH PRESSURE SPREADS SOUTHEAST FROM THE
NORTHERN PLAINS.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-
LMZ745...1 AM FRIDAY TO 1 PM FRIDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...1 PM
FRIDAY TO 1 PM SATURDAY.
GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-LMZ567-
LMZ868...7 AM FRIDAY TO 1 AM SUNDAY.
GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...4 AM FRIDAY TO 1 AM
SUNDAY.
&&
$$
