000
FXUS63 KLOT 051757
AFDLOT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1255 PM CDT SAT JUL 5 2008
.DISCUSSION...
155 AM CDT
WITH UPR TROF PASSAGE COMPLETE OVERNIGHT...HIGH PRESSURE SHUD WORK
DOWN THE LAKES INTO IL AND INDY THIS MRNG. INCREASING SUBSIDENCE AND
LESS CYCLONIC FLOW SHUD INHIBIT CU FORMATION TODAY UNLESS SOME SCT
FLAT SC EARLY IN THE AFTN SOUTH OF KANKAKEE.
AFTER ANOTHER CLEAR NIGHT SAT NGT...FOCUS TURNS TO THE NEXT CHC OF
RAIN LATE SUN NIGHT. WITH RIDGING OFF TO THE EAST ON SUNDAY...SFC
FLOW BECOMES MORE SOUTHERLY. THIS TAPS THE GULF AND FEEDS WARM MOIST
GULF AIR UP THRU TX AND THE LOWER MS VLY SUNDAY. A VIGOROUS LOW LVL
JET FROM SRN TX INTO THE PLAINS HIGHLIGHTS AN ELEVATED WARM FRONT
GENERATED OVER IA AND NEB BY SUN AFTN...WITH A RATHER BROAD AREA OF
ISENTROPIC ASCENT. LIKELY TO SEE SOME MCS DEVELOPMENT ON THE NOSE OF
THE STRONG THERMAL RIDGE POKING IN THAT AREA. THICKNESS LINES
GENERALLY LINED UP TO GUIDE STORMS SE INTO WRN IL SUN NGT BEFORE
DYING OUT IN THE PREDAWN MONDAY. HOWEVER WITH OUTFLOWS SET UP ACROSS
THE AREA FROM TSTM ACTIVITY THE NIGHT BEFORE AND AN ELEVATED WARM
FRONT STILL IN THE MS VLY...TSTMS ARE BOUND TO REDEVELOP IN MONDAYS
HEATING AND CONTINUE MONDAY NIGHT INTO TUESDAY WITH THE APPROACH OF
A COLD FRONT OUT OF THE NORTHERN PLAINS. POPS ARE LESS THAN 50
PERCENT NOW BUT MAY FIND THEM RISING TO 70 TO 80 PERCENT BEFORE
MONDAY ARRIVES.
LATEST MODEL RUN IS A BIT MORE VIGOROUS NOW WITH FROPA TUES NGT BY
INDICATING MORE DECENT H8 TEMP FALLS ON WEDNESDAY. BUT WITH RIDGING
WORKING BACK ACRS THE PLAINS...THE WARM UP BACK INTO THE MID 80S
RETURNS ON FRIDAY.
RLB
&&
.AVIATION...
1255 PM CDT
A RIDGE OF HIGH PRESSURE FROM LOWER MICHIGAN INTO THE OHIO RIVER
VALLEY WILL CONTINUE TO TRACK OFF TO THE EAST TONIGHT. WINDS HAVE
GENERALLY BEEN LESS THAN 10 KNOTS THIS AFTERNOON AND WITH THE SFC
RIDGE AXIS CONTINUING MOVING TO THE EAST TODAY...A SOUTHEAST WIND
DIRECTION WILL CONTINUE TO BE FAVORED. A FAIRLY STRONG UPPER LEVEL
SHORT WAVE CURRENTLY EXTENDING FROM SOUTHERN SASKATCHEWAN INTO
EASTERN MONTANA WILL CONTINUE TO SKIRT ALONG US CANADIAN BORDER THIS
AFTERNOON INTO TONIGHT TAKING A SURFACE TROUGH TO EASTERN MINNESOTA
BY MIDDAY SUNDAY. SOUTHEAST WINDS THIS EVENING...WILL VEER TO THE
SOUTH AND THEN SOUTHWEST ON SUNDAY MORNING AS THIS TROUGH OF LOW
PRESSURE MOVES ACROSS THE NORTHERN GREAT LAKES. LOW LEVEL SOUTH
SOUTHWEST WINDS SHOULD BE STRONG ENOUGH TOMORROW TO PREVENT LAKE
BREEZE FROM REACHING TERMINALS. MAY NEED TO WATCH GYY HOWEVER
DEPENDING ON THE ONSET OF STRONGER SOUTHERLY WINDS TOMORROW
MORNING...WITH MODIFIED LAKE BREEZE POSSIBLE AT THIS LOCATION.
THROUGH SUNDAY MORNING...SOUTH WIND SPEEDS OF AROUND 10
KNOTS...ALTHOUGH AT RFD WILL LIKELY HAVE SOME GUSTS AROUND 15 KNOTS
BY MID TO LATE MORNING. LIMITED CU DEVELOPMENT WILL ALSO BE POSSIBLE
TOWARD MIDDAY SUNDAY...BUT THERMODYNAMIC PROFILES WOULD SUGGEST NOT
MUCH VERTICAL DEVELOPMENT AND BASES SOMEWHERE BETWEEN 4-5K FT.
MARSILI
&&
.MARINE...
204 AM CDT
A RIDGE OF HIGH PRESSURE SITTING ACROSS CENTRAL LAKE MICHIGAN WILL
SLOWLY MOVE EASTWARD ACROSS THE GREAT LAKES TODAY INTO SATURDAY
NIGHT.
WINDS HAVE ALREADY GONE MORE SOUTHERLY ACROSS THE NORTHERN HALF OF
THE LAKE WITH THE SOUTHERN HALF SOON TO FOLLOW SUIT. AS A LOW
PRESSURE SYSTEM TRACKS ACROSS SOUTHERN CANADA IT WILL DROP A COLD
FRONT DOWN INTO THE NORTHERN HALF OF THE LAKE ON MONDAY NIGHT.
THIS FRONT WILL STALL OUT AND THEN LIFT BACK NORTHWARD AS A WARM
FRONT ON TUESDAY AS ANOTHER LOW PRESSURE SYSTEM TRACKS THROUGH THE
LAKES.
HALBACH
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
