332 AM CDT
SECOND VERSE SAME AS THE FIRST...OR IN THIS CASE THE
THIRD...FOURTH...FIFTH...AND SIXTH VERSE WITH CONTINUED SUNSHINE AND
DRY WEATHER. BROAD ANTI-CYCLONIC FLOW CONTINUES TO DOMINATE THE
SENSIBLE WEATHER FOR THE GREAT LAKES REGION STRETCHING EAST THROUGH
THE OHIO VALLEY AND MID-ATLANTIC.
EARLY THIS MORNING IR IMAGERY CONTINUED TO INDICATE SOME PATCHY
CIRRUS NEAR US...FORTUNATELY STRATUS WAS NOT AT US. WITH THE LACK OF
A PRESSURE GRADIENT...WINDS HAVE IN MANY LOCATIONS GONE CALM. THIS
HAS ALLOWED TEMPERATURES TO RADIATE INTO THE LOW/MID 50S...AND JUST
BEFORE SUNRISE A FEW SITES WILL MOST LIKELY DIP TO AROUND 50 OR
POSSIBLY THE UPPER 40S. IT DOES NOT LOOK FAVORABLE FOR FOG
DEVELOPMENT WITH A LARGE TEMP/DEW PT SPREAD...HOWEVER A FEW
PROTECTED AREAS AND SITES NEAR VEGETATION COULD SEE SOME PATCHY
GROUND FOG FORM. THIS FOG WILL REMAIN IN A VERY THIN LAYER NEAR THE
SURFACE AND SHOULD NOT POSE A LARGE REDUCTION TO VSBYS. ANY FOG THAT
DEVELOPS WILL NOT LINGER BEYOND AN HOUR AFT SUNRISE.
EXPECT TEMPS TO BE SIMILAR TO THE PAST FEW DAYS...AND HAVE TRENDED A
HAIR WARMER THAN GUIDANCE. ATMOSPHERIC PARCELS REMAIN PARCHED GIVEN
SUCH A DRY STRETCH OF WEATHER...MINIMAL SOLAR SHIELDING...AND LACK
OF MOISTURE BEING ADVECTED INTO THE REGION...THAT IT IS SAFE TO
ASSUME A COUPLE DEGREES ABOVE GUIDANCE WILL WORK YET AGAIN THIS AFTN
AND FRI. MOST LOCATIONS SHOULD SEE 80 TO 84 DEG BOTH DAYS...NEAR
CARBON COPIES OF EACH OTHER. THE ONLY EXCEPTION COULD BE THE
IMMEDIATE LAKESHORE WHERE A SOUTHERLY FLOW AND POSSIBLE LAKE BREEZE
COULD LIMIT TEMPS IN THE UPR 70S.
BASED ON THE AFOREMENTIONED CONCERNING DRY WEATHER...AND LACK OF
MOISTURE ADVECTION INTO OUR CWFA...AFTN RH VALUES MAY YET AGAIN DIP
INTO THE MID/UPR 20 PERCENT RANGE FOR MANY LOCATIONS. GUIDANCE
CONTINUES TO SUGGEST DEW POINTS WILL RISE A FEW DEGREES...HOWEVER
FEEL THIS IS BEING OVERDONE. THUS HAVE TRENDED DRIER WITH LOWER DEW
POINTS IN THE MID/UPR 40S. WINDS WILL REMAIN LGT THIS AFTN...WHICH
WILL AID IN PREVENTING RH VALUES FROM TUMBLING FURTHER. MINIMAL
MIXING IS ALSO EXPECTED THIS AFTN.
OVERNIGHT TEMPS WILL REMAIN MILD IN THE LOW/MID 50S FOR MOST...WITH
UPR 50S POSSIBLY 60 DEG FOR THE IMMEDIATE LAKESHORE. THIS WILL BE
THE SAME CASE FOR FRIDAY.
SATURDAY THROUGH WEDNESDAY...
ENSEMBLES CONTINUE TO DEMONSTRATE MINIMAL SPREAD AMONGST MEMBERS IN
THE FIRST FEW PERIODS OF THE EXTENDED...THEN BEGIN TO DIVERGE AS IT
APPEARS THE BLOCKING RIDGE WILL BEGIN TO WEAKEN AND SLIDE EAST
TUE/WED. PRIOR TO THE POSSIBLE ARRIVAL OF THE TROUGH AXIS...DRY
WEATHER WILL YET AGAIN BE THE DRIVING STORY WITH ABOVE NORMAL TEMPS.
HEAT CAPACITY WILL REMAIN MINIMAL...THUS LARGE DIURNAL SWINGS IN
AFTN TEMPS WILL OCCUR. A FEW OPERATIONAL SOLUTIONS BEGIN TO SUGGEST
THE LEADING EDGE OF THE TROUGH WILL ARRIVE TUE WITH INCREASED
MOISTURE...AND THE FIRST CHANCES FOR PRECIP. WHILE SEVERAL SOLUTIONS
INDICATE PRECIP...CONFIDENCE THAT THIS WILL OCCUR IS VERY LOW AT
THIS TIME. THUS HAVE ONLY GONE WITH SLIGHT CHANCE WORDING.
BEACHLER
&&
.FIRE WEATHER...
332 AM CDT
CONTINUED DRY WEATHER THROUGH THE NEXT FEW DAYS WITH DEW POINTS
HOVERING IN THE MID/UPR 40S...POSSIBLY RISING TO 50 DEGREES
FRI AFTERNOON ACROSS PORTIONS OF NORTHERN ILLINOIS. WINDS AGAIN
TODAY WILL REMAIN LIGHT FROM THE SOUTH AROUND 10 MPH. AFTERNOON
TEMPERATURES ARE EXPECTED TO WARM TO THE LOWER 80S FOR MUCH OF THE
AREA...COUPLED WITH THE FORECAST DEW POINTS AND RELATIVE HUMIDITY
VALUES WILL FALL THIS AFTERNOON TO THE 20 TO 30 PERCENT RANGE
ACROSS MUCH OF THE AREA. 20 FT WINDS ARE EXPECTED TO BE SIMILAR TO
THE SFC CONDS.
FRIDAY WILL SEE SOME CHANGES WITH INCREASED WINDS...AROUND 15
MPH...AND BETTER MIXING. DEW POINTS MAY RISE INTO THE LOWER
50S...WHICH WILL AID IN KEEPING AFTERNOON RELATIVE HUMIDITY VALUES
BETWEEN 30 AND 40 PERCENT. HOWEVER CONFIDENCE IS LOW...AS
GENERALLY INCREASED WINDS AND LACK OF MOISTURE INDICATES DEW
POINTS WILL FALL IN THE AFTERNOON. THUS THE POTENTIAL FOR LOWER
RELATIVE HUMIDITY VALUES ACROSS ALL OF NORTHERN ILLINOIS.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 08Z...
* WIND DIRECTIONS THIS AFTERNOON WITH A POSSIBLE LAKE BREEZE.
KJB
//DISCUSSION...UPDATED 06Z...
WINDS WILL BE THE PRIMARY CONCERN TODAY...ALBEIT MINOR. THE
SURFACE FLOW WILL BE SOUTH SOUTHEASTERLY TODAY ALONG THE BACK SIDE
OF THE SURFACE RIDGE OF HIGH PRESSURE ACROSS THE EASTERN GREAT
LAKES. IT APPEARS THE WINDS WILL BE SLIGHTLY HIGHER TODAY AS THE
SURFACE GRADIENT INCREASES ACROSS THE CENTRAL CONUS IN RESPONSE TO
DEEPENING LOW PRESSURE ACROSS THE NORTHERN HIGH PLAINS. BECAUSE OF
THIS...THE WINDS ARE EXPECTED TO REMAIN SOUTHEASTERLY THROUGH THE
DAY. HOWEVER...IT IS POSSIBLE THAT ANOTHER LAKE BREEZE COULD DEVELOP
LATER THURSDAY AFTERNOON AND CAUSE THE SYNOPTIC SOUTHEASTERLY WINDS
TO BACK MORE EASTERLY AT KORD AND KMDW. CONFIDENCE IN THE LAKE
BREEZE EFFECTING ORD AND MDW REMAINS LOW AT THIS TIME AS THE MAIN
INLAND PUSH MAY REMAIN NORTH OF THE TERMINALS.
OTHER THEN THE WINDS...NO ISSUES AGAIN TODAY AS SKIES REMAIN VFR.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 08Z...
* MEDIUM CONFIDENCE IN WIND FORECAST.
KJB
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY THROUGH TUESDAY...VFR.
&&
.MARINE...
325 AM CDT
WITH A LARGE STRONG HIGH FROM QUEBEC TO THE GULF OF MEXICO SLOWLY
SETTLING S TO OVER THE MID ATLANTIC STATES SAT AND DEEP LOW
PRESSURE LIFTING NE FROM THE NORTHERN AND CENTRAL ROCKIES ACROSS
MANITOBA THE PRESSURE GRADIENT WILL INCREASE SIGNIFICANTLY...
ESPECIALLY OVER CENTRAL AND NORTHERN PORTIONS OF LAKE MI FRI AND
SAT.
MODELS SHOW LOW LEVEL SW FLOW OF 20 TO 25 KT INCREASING TO 40+ KT
DURING FRI AND FRI NIGHT BUT THEY ALSO SHOW VERY WARM LOW LEVEL
AIR. WITH THE LAKE SURFACE HAVING COOLED TO 12 TO 15C THERE WILL
BE A SHALLOW STABLE LAYER OVER THE LAKE. THIS WILL SIGNIFICANTLY
LIMIT MIXING OF THE STRONG WINDS ALL THE WAY DOWN TO THE WATER.
WHILE THE WEST SHORES OF THE LAKE WILL SEE STRONGER WINDS
CARRYING OUT OVER THE WATER FROM WELL MIXED LOW LEVELS OVER THE
LAND ANTICIPATE PREVAILING WINDS FROM LATER FRI THROUGH SAT TO
REMAIN BELOW 25 KT S AND BELOW 30 KT CENTRAL AND N.
AS THE LOW MOVES FURTHER NE TO HUDSON BAY SAT THE PRESSURE
GRADIENT WILL BE RELAXING AND WINDS SLACKENING.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
