Area Forecast Discussion
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000
FXUS63 KLOT 032047
AFDLOT

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
247 PM CST TUE MAR 3 2015

.SHORT TERM...
247 PM CST

THROUGH THURSDAY...

SOMEWHAT BAGGY COLD FRONT WILL MOVE ACROSS THE REGION THIS EVENING
AND USHER IN PROGRESSIVELY COLDER AIR MASS THROUGH THE NIGHT. AHEAD
OF THE INTO THE EARLY-MID EVENING ANTICIPATE LOW STRATUS HANGING
AROUND AND LIKELY RESULTING IN NEARLY STEADY TEMPS AND HAVE GONE A
BIT ABOVE HOURLY GUIDANCE TEMPS HANGING ONTO 30S INTO THE EARLY
EVENING OVER MOST OF THE CWA BEFORE BOTTOM DROPS OUT LATE TONIGHT.
SOME PARTIAL CLEARING IS EXPECTED OVERNIGHT BUT SOME MID-HIGH CLOUDS
WILL MOVE IN AS WELL...SO NOT CURRENTLY EXPECTING SKIES TO GO CLEAR.

A COUPLE DAYS OF UNSEASONABLY COLD WEATHER LOOK TO BE ON TAP
WEDNESDAY AND THURSDAY. WEDNESDAY NIGHT HAS POTENTIAL TO GIVE
CHICAGO`S RECORD LOW A RUN FOR ITS MONEY...THOUGH GUIDANCE SUGGESTS
MID-HIGH LEVEL CLOUDINESS COULD BE RATHER EXTENSIVE FOR MUCH OF THE
NIGHT AND WINDS STAYING UP A BIT. BOTH OF THESE FACTORS COULD KEEP
TEMPS FROM REALIZING THEIR FULL FRIGID POTENTIAL...THOUGH ANY LATE
NIGHT CLEARING COULD ALLOW FOR LAST MINUTE DROPS IN TEMPS. ARCTIC
HIGH WILL BE NEAR BY THURSDAY WITH HEART OF THE ARCTIC AIR MASS
OVERHEAD TO START THE DAY...SUGGESTING THAT HIGHS COULD THREATEN
RECORD LOW MAX TEMPS. FULL SUNSHINE THURSDAY WITH LOWER ALBEDO IN
CHICAGO AND RFD METRO AREAS SHOULD ALLOW TEMPS TO MODERATE A BIT
ABOVE GUIDANCE AND HAVE TRENDED HIGHS EVER SO SLIGHTLY UPWARD.

IZZI

&&

.LONG TERM...
247 PM CST

THURSDAY NIGHT THROUGH TUESDAY...

THURSDAY NIGHT COULD BE ONE OF THOSE NIGHTS THAT SEE TEMPERATURES
CRASH DURING THE EVENING HOURS GIVEN CLEAR SKIES AND PROXIMITY OF
THE HIGH. HIGH DOES SCOOT OFF TO THE EAST OVERNIGHT AND SOUTHERLY
WINDS LOOK TO DEVELOP AFTER MIDNIGHT WHICH SHOULD ALLOW TEMPS TO
LEVEL OFF AND THEN BEGIN TO SLOWLY RISE PRIOR TO SUNRISE AND DID
REFLECT THIS TREND IN THE HOURLY TEMP GRIDS.

FRIDAY INTO NEXT WEEK LOOK TO BE FAIRLY QUIET PERIOD WITH A TREND TO
NORMAL AND THEN POTENTIALLY EVEN ABOVE NORMAL TEMPS BY EARLY NEXT
WEEK. STRONG MARCH SUN AND TEMPS WARMING ABOVE FREEZING THIS WEEKEND
DURING THE DAYTIME SHOULD BEGIN THE PROCESS OF CHIPPING AWAY AT THE
DEEP SNOW PACK/GLACIER THAT HAS BLANKETED THE REGION SINCE THE EARLY
FEBRUARY BLIZZARD. MEDIUM RANGE GUIDANCE CONTINUES TO SUGGEST AN
EXTENDED PERIOD OF ABOVE AVERAGE TEMPERATURES HEADING INTO THE
MIDDLE OF THE MONTH...THE QUICKER THE SNOW PACK MELTS THE WARMER
TEMPS COULD POTENTIALLY GET AS A MEAN RIDGE IS PROGGED TO DEVELOP OF
THE NATION`S MID SECTION.

IZZI

&&

.CLIMATE...

WE COULD COME CLOSE TO A COUPLE RECORDS WITH THIS NEXT COLD SPELL.
THE ONES WITH STARS (*) ARE MOST VULNERABLE.

  WED 3/4  THU 3/5
ROCKFORD

RECORD LOW-11 (2002)-11 (2002)
RECORD LOW MAX 14 (2002)* 17 (1960)*

CHICAGO
RECORD LOW-12 (1873)  0 (1978)*
RECORD LOW MAX   17 (1890)       12 (1901)

&&

.AVIATION...

//ORD AND MDW CONCERNS...UPDATED 20Z...

* WSWLY WINDS GUSTING TO 20-25KT UNTIL FROPA EARLY THIS
  EVENING...THEN WIND SHIFTING TO WNWLY OVERNIGHT AND NWLY
  TOMORROW GUSTING TO 20KT.

* IFR VIS IN -DZ/BR FOR A COUPLE MORE HOURS...IMPROVING TO MVFR IN
  BR UNTIL FROPA.

* IFR CIGS UNTIL FROPA...THEN IMPROVING TO MVFR OVERNIGHT INTO
  EARLY TOMORROW MORNING.

KREIN

//DISCUSSION...UPDATED 18Z...

WARM...MOIST ADVECTION HAS SET UP ACROSS THE REGION IN ADVANCE OF
A STRONG COLD FRONT EXTENDING FROM NERN MN THROUGH CNTRL IOWA.
CIGS HAVE BECOME MORE UNIFORMLY 005-007 ACROSS THE REGION AS
TEMPERATURES RISE INTO THE LOWER TO MIDDLE 30S AND DEWPOINTS RISE
INTO THE UPPER 20S TO LOWER 30S. DRY AIR OVERSPREADING THE NEARLY
SATURATED LOWER LEVELS HAS TRANSITIONED PCPN OVER TO DZ WHERE SFC
TEMPS ARE ABOVE FREEZING AND FZDZ WHERE TEMPS REMAIN BELOW
FREEZING. A FEW ISOLD POCKETS OF MORE STEADY RAIN REMAIN...BUT
SHOULD BE BRIEF. EXPECT THAT MDW/GYY HAVE ALREADY TRANSITIONED
OVER TO DZ...WHILE ORD/DPA/RFD REMAIN UNDER FZDZ. A SFC WAVE ALONG
THE FRONT IS QUICKLY TRACKING NEWD ALONG THE FRONT AND HAS ALREADY
MOVED INTO WISCONSIN...WITH A 7MB/3HR PRESSURE RISE/FALL COUPLET
GENERATING WIND GUSTS TO 25KT ACROSS THE REGION. EXPECT THE DZ TO
END AS THE SFC LOW CONTINUES NEWD INTO THE UPPER GREAT
LAKES...WITH LATEST RADAR IMAGERY SHOWING A RELATIVELY SHARP BACK
EDGE TO THE PCPN MOVING EWD THROUGH NCNTRL IL. CONDITIONS SHOULD
GRADUALLY IMPROVE TO MVFR AND VFR FOLLOWING THE FROPA AS
COLDER...DRIER AIR FILTERS ACROSS THE REGION. FOLLOWING THE
FROPA...EXPECT THAT STRONG ADVECTION BEHIND THE FRONT WILL HELP
DRIVE NWLY GUSTS TO 25KT TOMORROW.

KREIN

//ORD AND MDW CONFIDENCE...UPDATED 20Z...

* MEDIUM CONFIDENCE IN TIMING PCPN ENDING.

* LOW CONFIDENCE IN TIMING OF CIGS/VIS IMPROVING TO MVFR AND VFR.

* HIGH CONFIDENCE IN WIND TRENDS.

KREIN

//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...

WEDNESDAY NIGHT THROUGH FRIDAY...VFR.

SATURDAY THROUGH MONDAY...MVFR CIGS POSSIBLE.

RATZER

&&

.MARINE...

230 PM...LOW PRESSURE OVER THE NORTHERN LAKES WILL MERGE WITH
DEEPER LOW PRESSURE OVER NORTHERN ONTARIO TONIGHT AND THEN MOVE
INTO QUEBEC WEDNESDAY MORNING. WINDS WILL BE SHIFTING WESTERLY
OVER THE NEXT FEW HOURS AND THEN MORE NORTHWEST ACROSS THE
SOUTHERN PART OF THE LAKE OVERNIGHT. THE GRADIENT WILL REMAIN
TIGHT AS HIGH PRESSURE BUILDS ACROSS THE NORTHERN AND CENTRAL
PLAINS WEDNESDAY AND WEDNESDAY NIGHT AND COMBINED WITH RETURNING
COLD AIR...WINDS TO 30KT LOOKS REASONABLE. AS THE HIGH MOVES EAST
ACROSS THE SOUTHERN LAKES AND OHIO VALLEY THURSDAY NIGHT INTO
FRIDAY...THE GRADIENT WILL TIGHTEN ACROSS THE WESTERN LAKES WITH
SOUTHWEST WINDS INCREASING BACK TO 30KT WITH SOME POTENTIAL FOR
LOW END GALES. THESE WINDS WILL GRADUALLY DIMINISH FRIDAY NIGHT AS
THE GRADIENT BEGINS TO WEAKEN. CMS

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
     UNTIL 6 PM WEDNESDAY.

&&

$$

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