847 PM CDT
WITH HIGH PRESSURE CENTERED ACROSS THE REGION...IT IS BASICALLY A
WX NIL SCENARIO...AND WILL REMAIN THAT WAY FOR THE MAJORITY OF THE
WEEK. TWEAKED THE DIURNAL CURVES SOME TO ACCOUNT FOR TEMPS QUICKLY
FALLING IN THE DRY AIRMASS. CURRENT MIN T/S ARE BELOW ANY GUIDANCE
AND ARE LOOKING ON TRACK AND DIDNT REQUIRE ANY HEDGING. GENERAL
40/S ALONG THE LAKE WITH MID TO UPPER 30/S IN ALL OUTLYING AND
RURAL AREAS CAN BE EXPECTED OVERNIGHT. WITH HOW DRY THE AIRMASS
MIXED OUT TO THIS AFTERNOON...THINK THAT FOG WILL HAVE A HARDER
TIME FORMING TONIGHT...WHEN COMPARED TO LAST NIGHT. OTHERWISE
PATCHY FROST LOOKS POSSIBLE IN THE PREVIOUSLY MENTIONED LOCATIONS.
UPDATED ZONES AND GRIDS WILL BE OUT THE DOOR MOMENTARILY.
SHEA
&&
.PREV DISCUSSION...
303 PM CDT
QUIET AND DRY WEATHER WILL PERSIST THROUGH THE WEEK AND INTO NEXT
WEEKEND WITH A SLOW BUT STEADY WARMING TREND COMMENCING. AFTERNOON
WATER VAPOR IMAGERY SHOWS A VERY AMPLIFIED PATTERN ACROSS NORTH
AMERICA AND THE ADJACENT AREAS OF THE ATLANTIC AND PACIFIC.
HURRICANE OPHELIA CONTINUES TO RACE NORTH AND NORTHEASTWARD OFF THE
NEWFOUNDLAND COAST WHILE A LARGE CUTOFF UPPER LOW SPINS OVER THE
MID-ATLANTIC STATES. HIGH AMPLITUDE AND EXPANSIVE UPPER RIDGING IS
POSITIONED OVER THE CENTER OF THE CONUS AND IS VERY SLOWLY DRIFTING
EASTWARD AS A DEEP UPPER TROUGH PUSHES TOWARD THE WEST COAST. AT THE
SURFACE...HIGH PRESSURE EXTENDS FROM NORTHERN LAKE MICHIGAN
SOUTHWARD INTO THE DEEP SOUTH.
THE SHORT TERM CONCERN IS LOW TEMPERATURES TONIGHT. THE CENTER OF
THE HIGH WILL BE SOUTH OF THE AREA BUT THE BROAD RIDGE AXIS WILL
REMAIN OVERHEAD TONIGHT. THIS WILL ALLOW WINDS TO DROP OFF ACROSS
THE AREA...ESPECIALLY WEST WHICH WILL COMBINE WITH CLEAR TO MOSTLY
CLEAR SKIES TO ALLOW FOR DECENT RADIATIONAL COOLING. GUIDANCE
APPEARS TO BE TOO WARM FOR MOST OF THE AREA WITH LOWEST TEMPS OF
AROUND 40. GIVEN THE RADIATIONAL SET UP AND THE FACT THAT DEW POINTS
HAVE MIXED OUT TO THE LOW 30S OR LOWER FOR MANY AREAS HAVE OPTED
TO LOWER OVERNIGHT TEMPS WEST AND SOUTH OUTSIDE OF THE CHICAGO
METRO. THUS EXPECT MID/UPPER 30S WEST AND UPPER 30S SOUTH. STILL
HAVE CONCERNS THAT THIS MAY NOT BE COOL ENOUGH BUT WITH POTENTIAL
FOR A VERY LIGHT BREEZE EVEN UNDER THE RIDGE AND SOME PERIODIC THIN
CIRRUS WILL HOLD OFF FROM GOING MUCH LOWER FOR NOW. WILL INCLUDE
PATCHY FROST ACROSS AREAS OUTSIDE THE MOST DENSE URBAN AREAS AND
CLOSE TO LAKE MICHIGAN.
THE WEST COAST TROUGH WILL CONTINUE TO MAKE EASTWARD PROGRESS OVER
THE NEXT DAY OR TWO WHICH WILL HELP TO AMPLIFY THE RIDGE ACROSS THE
MIDDLE OF THE COUNTRY. THE EASTERN TROUGH WILL REMAIN ENTRENCHED
OVER THE MID-ATLANTIC/NEW ENGLAND. ULTIMATELY...THE PATTERN IS
EVOLVING INTO AN OMEGA BLOCK WHICH TRANSLATES TO SLOW CHANGES IN THE
UPPER FLOW OVERHEAD AND TRANQUIL WEATHER THROUGH THE WEEK. THE UPPER
RIDGE AXIS WILL MOVE EAST AND THEN REFORM TO THE WEST AS ENERGY
MOVES ACROSS ITS NORTHERN FLANK ACROSS CENTRAL CANADA AND WAVES
EJECT FROM THE WESTERN TROUGH WHICH WILL BE WORKING INTO THE FOUR
CORNERS REGION. THE BLOCK WILL BECOME BETTER ORGANIZED BY LATE WEEK
AS A MORE SIGNIFICANT UPPER TROUGH MOVES ONSHORE OVER CALIFORNIA AND
CUTS OFF OVER THE FOUR CORNERS.
AS A RESULT...DRY WEATHER IS EXPECTED THROUGH AT LEAST THE END OF
THE WEEK. THE SLOW PROGRESSION OF THE SYSTEM WILL MEAN A SLOW BUT
STEADY WARMING TREND AS THE SURFACE HIGH MOVES EAST AND LIGHT
SOUTHERLY FLOW RETURNS. HIGHS WILL BE RETURNING TO THE 70S FOR
WESTERN AND SOUTHERN AREAS OF THE CWA MONDAY WITH LOW TO MID 70S
FOR ALL AREAS TUESDAY. HIGHS WILL REMAIN IN THE 70S INTO THE
WEEKEND. ONE POTENTIAL FLY IN THE OINTMENT COULD BE
TUESDAY/WEDNESDAY AS THE WAVES FROM THE BUILDING WESTERN TROUGH MOVE
ALONG THE WESTERN AND NORTHERN PERIPHERY OF THE UPPER RIDGE. ITS
POSSIBLE...ALTHOUGH UNLIKELY...THAT ONE OF THESE WAVES COULD MOVE
CLOSE TO THE AREA AND BRING SOME INCREASED CLOUD COVER BUT LITTLE
MORE THAN THAT WITH A DRY LOWER ATMOSPHERE REMAINING IN PLACE. NEXT
WEEKEND LOOKS TO REMAIN DRY AS WELL WITH THE BLOCKING PATTERN
EXPECTED TO PROGRESS VERY SLOWLY KEEPING ANY PRECIP PRODUCING SYSTEM
TO THE WEST. IT DOES APPEAR THE BLOCK WILL TRY TO BREAK DOWN LATER
IN THE WEEKEND WHICH MAY RESULT IN A FRONTAL PASSAGE VERY LATE IN
THE WEEKEND OR MORE LIKELY EARLY NEXT WEEK.
MDB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* NONE.
ALLSOPP
//DISCUSSION...UPDATED 00Z...
A HIGH PRESSURE RIDGE WAS FROM LAKE SUPERIOR TO EAST TEXAS THIS
EVENING. THIS RIDGE BROUGHT LIGHT NORTH NORTHWEST WINDS TO THE AREA
TODAY. A LAKE BREEZE DEVELOPED AN HUNG UP NEAR MIDWAY AND EAST OF
OHARE LATE THIS AFTERNOON. THE BOUNDARY HAS SHIFTED BACK EAST OF
MIDWAY EARLY THIS EVENING. AS THE SUN GOES DOWN THE ATMOSPHERE
WILL DECOUPLE AND WINDS WILL BECOME NEARLY CALM. THE HIGH PRESSURE
RIDGE WILL SHIFT SLOWLY EAST TO A LAKE MICHIGAN TO LOWER
MISSISSIPPI VALLEY AXIS MONDAY. THIS WILL CAUSE WINDS TO BECOME
MORE NORTH NORTHEAST MONDAY. LAKE ENHANCEMENT WILL TURN WINDS MORE
NORTHEASTERLY AT ORD AND MDW MONDAY AFTERNOON BUT WINDS SHOULD
REMAIN LESS THAN 10 KTS.
CLEAR SKIES AND UNRESTRICTED VISIBILITY UNTIL FURTHER NOTICE.
ALLSOPP
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN ALL ASPECTS OF FORECAST.
ALLSOPP
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY THROUGH SATURDAY...VFR.
ALLSOPP
&&
.MARINE...
237 PM CDT
HIGH PRESSURE HAS MOVED ACROSS THE MID MISSISSIPPI VALLEY AND
WESTERN GREAT LAKES THIS AFTERNOON...ALLOWING WINDS TO CONTINUE TO
SUBSIDE. SOME WINDS OCCASIONALLY IN THE 10 TO 20 KT RANGE ARE
POSSIBLE THIS AFTERNOON AT THE FAR SOUTH/SOUTHEASTERN PORTION OF
LAKE MICHIGAN...BUT OTHERWISE WINDS 15 KTS OR LESS ARE EXPECTED
THROUGH THE REST OF THE WEEKEND AND FIRST HALF OF NEXT WEEK. THE
HIGH WILL SHIFT EAST OF LAKE MICHIGAN LATE TUESDAY ALLOWING WINDS TO
SHIFT TO THE SOUTH. SOUTHERLY WINDS MAY INCREASE BACK INTO THE 10 TO
20 KT RANGE FOR NORTHERN LAKE MICHIGAN FOR A PERIOD LATE WEDNESDAY
THROUGH FRIDAY...BUT NO SIGNIFICANT WINDS OR WEATHER SYSTEMS ARE
FORECAST THROUGH THE REMAINDER OF THE WEEK AS THE HIGH PRESSURE
AMPLIFIES AND REMAINS ANCHORED ACROSS THE REGION. BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
