1001 AM CDT
CHALLENGING FORECAST FOR THE REMAINDER OF THE DAY TODAY...IN
REGARDS TO LINGERING DRY AIR AND PRECIP CHANCES. IR IMAGERY THIS
MORNING CONTINUES TO INDICATE THIN POCKETS IN THE CLOUD
SHIELD...WHICH INDICATES LINGERING DRY AIR IN THE ATMOSPHERE.
REGIONAL RADAR MOSAIC CONTINUES TO DEPICT A CHANNEL OF SHOWERS
EXTENDING FROM ST LOUIS NORTH THROUGH WESTERN ILLINOIS AND INTO
WESTERN WISCONSIN. THIS AREA OF RAIN WAS SLIDING EAST...HOWEVER
RECENT TRENDS HAVE INDICATED THAT THE LEADING EDGE WAS ERODING
SLOWLY AS IT PUSHES INTO A MUCH DRIER ENVIRONMENT ACROSS
NORTHCENTRAL ILLINOIS. DEW PT DEPRESSIONS REMAIN LARGE ACROSS MOST
OF THE CWFA...ON THE ORDER OF 20 DEG. THE EXCEPTION IS EXTREME
NORTHCENTRAL AND NORTHWEST ILLINOIS WHERE DEPRESSIONS ARE IN THE
TEENS.
500MB TROUGH AXIS REMAINS UPSTREAM THIS MORNING...HOWEVER GUIDANCE
CONTINUES TO PUSH THIS FEATURE OVER FAR WESTERN ILLINOIS BY
MIDDAY. THEN CONTINUE TO PUSH EAST. ALONG THE LEE-SIDE OF THE
TROUGH A TONGUE OF DEEPER MOISTURE IS PROGGED...AND APPEARS TO BE
ARRIVING OVER THE CWFA ARND 21Z AND QUICKLY PUSHES NORTHEAST BY
00Z. HAVE MADE SOME ADJUSTMENTS TO LOWER QPF TOTALS GIVEN THE DRY
AIR INFLUENCE. TEMPS ALSO BROUGHT DOWN A COUPLE OF DEGREES IN
SPOTS...BUT OVERALL STILL LOOKS TO BE FROM AROUND 50 TO THE MID
50S.
BEACHLER
//PREV DISCUSSION...
347 AM CDT
MAIN CONCERNS/ISSUES ARE WITH PRECIP TRENDS TODAY INTO
TONIGHT...ALONG WITH A WARMING TREND ANTICIPATED THROUGH THE
MIDDLE PART OF THE WEEK.
LATEST SATELLITE IMAGERY DEPICTING CURRENT LONGWAVE TROUGH ACROSS
THE CENTRAL PLAINS DIGGING SOUTH ALONG WITH ATTENDANT SURFACE
TROUGH AND ASSOCIATED FRONTAL BOUNDARIES LOCATED NEAR
MINNESOTA/IOWA THIS MORNING. AS THESE FEATURES SHIFT EAST EARLY
THIS MORNING...SHOWERS CAN BE SEEN SPREADING EAST ACROSS PORTIONS
OF IOWA...AND EXPECT THESE SHOWERS AND CLOUD COVER TO MOVE EAST
ACROSS THE REGION WITH TIME TODAY. LATEST GUIDANCE IN FAIR
AGREEMENT WITH TAKING THIS UPPER LEVEL TROUGH AND SURFACE
REFLECTION EAST ACROSS SOUTHERN WISCONSIN BY LATER THIS AFTERNOON
INTO EARLY EVENING. AS THIS OCCURS...LARGE SCALE FORCING WILL
INCREASE MORE FROM WEST TO EAST ACROSS THE CWA WITH THE BEST
FORCING TO COME LATER THIS AFTERNOON. ALTHOUGH...LATEST SURFACE
OBSERVATIONS CONTINUE TO INDICATE A VERY DRY AIRMASS IN PLACE WITH
DEWPOINTS CURRENTLY IN THE MID 20S. LAST NIGHTS 00Z OBSERVED
SOUNDINGS FROM ACROSS THE AREA WERE ALSO SHOWING THIS DRY AIR MASS
WITH VERY DRY LOWER LEVELS. ALTHOUGH MOISTURE WILL BE ON THE
INCREASE INTO THIS AFTERNOON...DONT THINK THIS PRECIP SHIELD WILL
REALLY SHIFT OVERHEAD UNTIL THE MID TO LATE AFTERNOON. AS THIS
OCCURS...THE COLUMN WILL SATURATE AND MOST OF THE CWA SHOULD
OBSERVE SHOWERS. DID LOWER POPS JUST A LITTLE BRINGING THEM DOWN
TO LIKELY FOR THIS AFTERNOON...BUT DID NOT MAKE THIS CHANGE DUE TO
OVERALL CONFIDENCE. DID THIS MORE DUE TO THE FACT OF THIS DRIER
AIR IN PLACE AND THE POSSIBLE LIGHTER NATURE OF THESE SHOWERS IN
SOME PLACES. THE BEST CHANCES FOR PRECIP CONTINUE TO BE ACROSS THE
NORTHERN HALF OF THE CWA TIED CLOSER TO UPPER LEVEL TROUGH/SURFACE
LOW...WITH THESE AREAS ALSO OBSERVING MORE AMOUNTS. INSTABILITY
DURING THIS TIME FRAME WILL REMAIN NON EXISTENT ACROSS THE REGION
WITH PRECIP REMAINING SHOWERS. ALTHOUGH...LATEST HIGH RES DATA IS
HINTING AT THE POSSIBILITY OF SOME CONVECTIVE ELEMENTS FORMING ON
THE BACKSIDE OF THE MAIN PRECIP SHIELD...MORE TOWARDS THIS
EVENING. BASED ON LATEST DATA...THIS WOULD SEEM TO BE A SLIGHT
POSSIBILITY. MODELS INDICATING THAT DRIER AIR/STEEPER MID LEVEL
LAPSE RATES WILL POSSIBLY MOVE OVERHEAD DURING THIS TIME...THUS
CREATING CONVECTIVELY UNSTABLE CONDITIONS. AM NOT QUIET CONFIDENT
AS TO THESE EXACT DETAILS AT THIS TIME...SO HAVE OPTED TO LEAVE
OUT ANY MENTION OF THUNDER. A MORE LIKELY SCENARIO WOULD BE AN
INCREASE IN RAINFALL RATES AS OPPOSED TO ANY POSSIBLE THUNDER.
CLOSED UPPER LEVEL TROUGH LATE TONIGHT AND EARLY MONDAY SHOULD
BECOME MORE OPEN AND SLOWLY SHIFT EAST WITH TIME. SHOWERS WILL BE
ENDING DURING THIS TIME...BUT WITH CLOUD COVER TO POSSIBLY LINGER
INTO MONDAY AFTERNOON. THEN WITH THE DEPARTURE OF THIS UPPER LEVEL
TROUGH...RIDGING WILL BE ONGOING WITH A WARMER AIR MASS SHIFTING
OVER AND A DRY PERIOD EXPECTED INTO EARLY WEDNESDAY. WITH A STEADY
STREAM OF SOUTHERLY FLOW AND THERMAL AXIS SHIFTING ACROSS THE
REGION...HAVE RAISED POPS TUESDAY AND WEDNESDAY WITH HIGHS LOOKING
MORE LIKELY TO BE IN THE LOW TO MID 60S. WITH MODELS TRENDING MORE
TOWARDS A SLOWER PROGRESSION OF THE NEXT SYSTEM...WEDNESDAY TEMPS
AND CONDITIONS APPEAR TO BE ON THE UP. ALTHOUGH...FOR SURE
PRECIP/CLOUD COVER WILL BE ON THE INCREASE WEDNESDAY NIGHT INTO
THURSDAY AS THIS SYSTEM SHIFTS EAST.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 15Z...
* SOUTH WINDS GUSTING TO 25-30 KTS TODAY.
* CHANCE OF SPRINKLES OR SHOWERS MID-AFTERNOON INTO EARLY EVENING.
KREIN
//DISCUSSION...UPDATED 18Z...
MAIN CONCERN FOR THE REMAINDER OF THE AFTERNOON AND INTO THE EARLY
EVENING WILL FOCUS ON WINDS. AS THE SFC LOW CONTINUES TO MOVE EWD
INTO SERN MINNESOTA...SURFACE PRESSURE FALLS ON THE ORDER OF
3MB/3HRS ARE NOW CENTERED OVER NRN IL/SRN WI. SOUTH WINDS ACROSS
THE AREA ARE GUSTING TO 25KT...AND WITH SOME FILTERED SUNSHINE
OVER NERN IL/NWRN IN/SRN LAKE MICHIGAN...THERE WILL STILL BE THE
POTENTIAL FOR GUSTS APPROACHING 30KT THIS AFTERNOON. AS THE SFC
LOW WEAKENS AND LIFTS TO THE NORTHEAST TONIGHT...WINDS WILL
DECREASE AND VEER SOUTHWESTERLY TO WESTERLY BY TOMORROW.
THE ONE SIGNIFICANT CHANGE TO THE GOING FORECAST IS TO BACK OFF ON
PCPN POTENTIAL AT THE TERMINALS. THE LATEST RADAR IMAGERY SHOWS A
SPLIT IN THE PCPN PATTERN OVER NRN IL...WITH AREAS OF RAIN MORE
CONCENTRATED IN WISCONSIN AND CENTRAL IL...SOUTH OF THE TERMINALS.
THE LOW LEVELS HAVE BEEN VERY SLOW TO MOISTEN AND SFC DEWPOINTS
ARE STILL IN THE LOW 30S. SO...HAVE BACKED OFF PCPN MENTION TO
VCSH. THERE IS STILL A CHANCE OF SOME SPRINKLES OR LIGHT SHOWERS
ACROSS THE AREA...BUT NOW FEEL THAT THE CHANCES FOR WETTING RAIN
AT THE TERMINALS IS SMALL.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN SOUTH WINDS GUSTING TO 25-30 KTS TODAY.
* LOW CONFIDENCE IN SHRA THIS AFTERNOON.
* MEDIUM-HIGH CONFIDENCE IN PREVAILING CIGS REMAINING VFR.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...VFR.
TUESDAY...VFR.
WEDNESDAY...CHC SHRA...MAINLY VFR. CHANCE MVFR CIGS OVERNIGHT.
THURSDAY...CHC SHRA...MVFR CIGS POSSIBLE.
FRIDAY...VFR.
SATURDAY...CHC SHRA.
KREIN
&&
.MARINE...
256 AM CDT
SOUTH-SOUTHEAST GALES ARE EXPECTED THROUGH EARLY EVENING OVER THE
CENTRAL AND SOUTHERN PORTIONS OF LAKE MICHIGAN.
LOW PRESSURE OVER THE UPPER MISSISSIPPI VALLEY COMBINED WITH HIGH
PRESSURE OVER THE MID ATLANTIC REGION HAS RESULTED IN A STRONG
SURFACE PRESSURE GRADIENT ACROSS LAKE MICHIGAN TODAY WINDS
QUICKLY INCREASED TO GALE FORCE EARLIER TODAY AND GALES TO 35 KT
RANGE WILL LIKELY PERSIST INTO THE EARLY EVENING HOURS. THE LOW
WILL THEN WEAKEN...ALLOWING WINDS TO GRADUALLY DIMINISH OVERNIGHT.
A WEAK COLD FRONT ASSOCIATED WITH THE WEAKENING LOW WILL SWEEP
ACROSS LAKE MICHIGAN OVERNIGHT SETTING UP A PERIOD OF GENERALLY
SOUTHWESTERLY WINDS INTO WEDNESDAY MORNING. ANOTHER...STRONGER
COLD FRONT IS EXPECTED TO PUSH ACROSS THE LAKE WEDNESDAY AFTERNOON
AS STRONG HIGH PRESSURE BUILDS OVER THE SOUTHERN PLAINS AND THE
UPPER MISSISSIPPI VALLEY.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...GALE WARNING...LMZ080-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-
LMZ779-LMZ868-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878 UNTIL 9 PM
SUNDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM SUNDAY.
&&
$$
