Area Forecast Discussion
Issued by NWS Green Bay, WI

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FXUS63 KGRB 191621
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1121 AM CDT TUE AUG 19 2014

NEW INFORMATION ADDED TO UPDATE SECTION
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE

.UPDATE...
ISSUED AT 1121 AM CDT TUE AUG 19 2014

EXTENSIVE AREA OF LOW CLOUDS CONTINUE TO LINGER THIS MORNING...AS
500 MB LOW CONTINUES TO SLOWLY SHIFT ACROSS SOUTHWESTERN LAKE
SUPERIOR. THE UPPER LOW WILL SHIFT SLOWLY TO THE EAST ACROSS THE
UPPER PENINSULA OF MICHIGAN THIS AFTERNOON...THEN SLOWS DOWN
TONIGHT BEFORE SHIFTING GRADUALLY TO THE SOUTHEAST ON WEDNESDAY.

VARIOUS VORTICITY MAXIMA ROTATING AROUND THE LOW...COMBINED WITH
MEAN LAYER CAPES OF 500 TO 800 J/KG...WILL BRING SCATTERED TO
NUMEROUS SHOWERS AND SOME THUNDERSTORMS TO THE AREA THIS
AFTERNOON. HIGHEST POPS IN THE FAR NORTHEAST COUNTIES CLOSEST TO
THE UPPER LOW CENTER. BRIEF HEAVY RAINFALL IS POSSIBLE WITH THE
EXPECTED SLOW MOVEMENT OF ANY STORMS...ALONG WITH BRIEF GUSTY
WINDS AND SMALL HAIL.

CLOUDS WILL TRY TO BECOME MORE SCATTERED TO BROKEN THIS AFTERNOON
WITH DAYTIME HEATING...ESPECIALLY IN THE FAR SOUTHERN
COUNTIES...BUT LEANED MORE TOWARD BROKEN/OVERCAST SKY COVER
ELSEWHERE. KEPT HIGHS AROUND 70 IN THE FAR NORTHERN COUNTIES...TO
THE UPPER 70S IN THE SOUTHEAST HALF OF THE AREA. THESE MAY NEED TO
BE LOWERED A BIT IF CLOUDS REMAIN IN THE SOUTH.

.SYNOPSIS...
ISSUED AT 342 AM CDT TUE AUG 19 2014

STILL RATHER HUMID WITH SCATTERED SHOWERS AND THUNDERSTORMS
REDEVELOPING TODAY.

PRETTY TYPICAL LATE-SUMMER UPPER PATTERN EXPECTED DURING THE NEXT
WEEK. A SOMEWHAT DIFFUSE LOW AMPLITUDE BAND OF WESTERLIES IS ACRS
THE NRN CONUS. A GRADUAL AMPLIFICATION IS EXPECTED TO OCCUR DURING
THE NEXT SEVERAL DAYS...WITH TROF CONSOLIDATING AND DEEPENING OVER
THE INTERMOUNTAIN WEST...AND DOWNSTREAM RIDGING STRENGTHENING FM
THE LOWER MISSISSIPPI VALLEY NNEWD ACRS THE LOWER GREAT LAKES.
ENERGY SHEARING OUT OF THE WRN TROF WL FLATTEN THE ERN RIDGE
DURING THE WEEKEND...LEAVING A STRONGER LOW AMPLITUDE WLY OR WSWLY
UPR FLOW ACRS THE NRN CONUS BY THE EARLY TO MIDDLE PART OF NEXT
WEEK.

THE PATTERN LOOKS MORE FAVORABLE FOR PCPN THAT WHAT WE/VE HAD FOR
MUCH OF THE SUMMER. THERE WL BE NUMEROUS OPPORTUNITIES FOR PCPN AS
MOIST UNSTABLE AIR WL RESIDE ACRS THE AREA AT TIMES AND AT LEAST
REMAIN RELATIVELY CLOSE AT OTHERS. PCPN AMNTS FOR THE NEXT 7 DAYS
ARE LIKELY TO END UP ABV NORMAL. TEMPS WL START OUT NR NORMAL...
THEN RISE TO SOMEWHAT ABV NORMAL FOR LATE IN THE WEEK AND THE
WEEKEND...BEFORE FALLING BACK A LITTLE NEXT WEEK. IT WL ALSO BE
RATHER HUMID MUCH OF THE TIME.
&&

.SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY
ISSUED AT 342 AM CDT TUE AUG 19 2014

MCS WL EXIT THE AREA THIS MORNING. WL ALIGN POPS AND WX BASED ON
RADAR TRENDS AT ISSUANCE TIME. SOME FOG AND ST WL LIKELY FORM IN
THE WAKE OF THE DEPARTING PCPN. NOW THAT SIG RAINS HAVE
OCCURRED...WL NEED TO KEEP A CLOSE WATCH ON THE POSSIBILITY FOR
SOME DENSE FOG. CENTRAL WI SEEMS MOST AT RISK OF THAT EARLY THIS
MORNING.

UPR LEVEL LOW WL TRACK TOWARD UPPER MICHIGAN TDA...AS WK SFC WV
MVS ACRS THE AREA THIS MORNING...THEN BEGINS TO SHIFT OFF TO THE E
THIS AFTN. LINGERING MOISTURE AND BREAKS IN THE CLDS WL ALLOW THE
ATM TO RECOVER TDA. THE STRONGEST QG FORCING WL BE TO OUR E...BUT
IT LOOKS LIKE SOME LOW-LEVEL CONVERGENCE WL BE FOCUSED OVER THE E
FOR THE AFTN. WL KEEP AT LEAST CHC POPS ACRS THE N ALL DAY AS
REMNANTS OF UPR DEFORMATION ZONE WL SHIFT INTO THAT AREA. ACRS
THE REST OF THE AREA...WL START THE DAY WITH FAIRLY LOW
POPS...THEN TAKE THEM UP TO SCT OR NMRS CATEGORIES FOR THE AFTN.
TSRA AGAIN POSSIBLE. LDS INDICATED QUITE A FEW STRIKES INVOF UPR
LOW YDA AFTN.

PCPN CHCS WL DECR FM SE-NE TNGT...THOUGH WL NEED TO KEEP SOME CHC
GOING IN THE NE ALL NGT AND THROUGH WED AS THE WEAKENING UPR LOW
IS EXPECTED TO SLOW AS IT REACHES ERN UPPER MICHIGAN.

BLEND OF TOP PERFORMING GUIDANCE TEMPS WAS VERY SIMILAR TO PREV
FCST...SO NO SIG CHGS THERE.

.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
ISSUED AT 342 AM CDT TUE AUG 19 2014

AFTER A DRY WEDNESDAY EVENING...THERE IS A SMALL CHANCE OF
SHOWER/STORMS LATER WEDNESDAY NIGHT OVER PARTS OF CENTRAL AND EAST
CENTRAL WISCONSIN AS A WARM FRONT LIFTS NORTHWARD INTO SOUTHERN
WISCONSIN. IN ADDITION...AS A MID LEVEL RIDGE DRIFTS EAST OF THE
AREA...AS SHORT WAVE TROUGH AXIS IN THE SOUTHWEST FLOW OVER THE
NORTHERN AND CENTRAL PLAINS WILL TRACK NORTHEASTWARD OVER THE
STATE. MOST MODELS IN AGREEMENT WITH LIFTING MOST OF THE PCPN
NORTHEAST OF THE STATE THURSDAY NIGHT. MODEL SOLUTIONS DIVERGE
AFTER THIS DUE DIFFERENCES ON THE AMPLITUDE OF THE BUILDING UPPER
RIDGE. THIS UPPER RIDGE DIFFERENCE SPILLS INTO THE BOUNDARY LAYER
AS TO THE LOCATION OF THE SURFACE WARM FRONT. THE ECMWF LIFTS A
500 MB 588 HEIGHT LINE INTO SOUTHERN WISCONSIN FOR A CONSIDERABLY
WARMER SOLUTION...WHILE THE GEM WAS MORE ZONAL. DUE TO THESE
INCONSISTENCIES...CONFIDENCE IS LOW AT THIS TIME.

EVENTUALLY THE RIDGE BREAKS DOWN AND A COLD FRONT IS PROGGED TO
DROP OVER THE REGION LATE IN THE WEEKEND OR INTO EARLY NEXT WEEK
FOR A PERIOD OF DRY WEATHER AND COOLER BUT NORMAL TEMPERATURES.

DEPENDING ON PRECIPITATION AND CLOUDS FOR ANY GIVEN DAY...
TEMPERATURES SHOULD AVERAGE A LITTLE ABOVE NORMAL LATE THIS WEEK
AND INTO THE WEEKEND THEN FALL BACK TO NORMAL FOR THE START OF THE
NEW WORK WEEK. IF MID LEVEL CAPPING IS STRONG AND THE UPPER RIDGE
BECOMES MORE ROBUST...SOME MAX TEMPS MAY REACH THE UPPER 80S LATE
THIS WEEK AND INTO SATURDAY.
&&

.AVIATION...
ISSUED AT 1121 AM CDT TUE AUG 19 2014

AREA OF MAINLY MVFR CEILINGS MAY BECOME MORE SCATTERED TO BROKEN
ACROSS TAF SITES THIS AFTERNOON WITH DAYTIME HEATING.
STILL...AT LEAST BROKEN SKIES ARE LIKELY TO LINGER...ESPECIALLY
AT RHINELANDER. THEY MAY BECOME VFR CATEGORY FOR A TIME LATER
THIS AFTERNOON INTO EARLY EVENING.

SCATTERED SHOWERS AND SOME THUNDERSTORMS ARE EXPECTED THIS
AFTERNOON INTO EARLY THIS EVENING...WITH TROUGH OF LOW PRESSURE
CROSSING THE REGION. WILL USE VICINITY SHOWER/THUNDER WORDING IN
TAFS FOR NOW. MAY SEE BRIEF HEAVY RAINFALL/WIND GUSTS AND SMALL
HAIL IN STRONGEST STORMS.

CHANCES FOR SHOWERS WILL GRADUALLY DIMINISH ACROSS TAF SITES
TONIGHT INTO WEDNESDAY...AS TROUGH OF LOW PRESSURE MOVES AWAY.
LIGHT WINDS AND LINGERING MOISTURE WILL BRING ANOTHER NIGHT OF LOW
CEILINGS WITH SOME FOG DEVELOPMENT. SHOULD SEE IFR
CEILINGS/VISIBILITIES...WITH LIFR POSSIBLE AT TIMES. DENSE FOG IS
NOT OUT OF THE QUESTION...THOUGH LOW CLOUDS MAY LIMIT THIS RISK TO
LOW LYING AREAS.

SHOULD SEE MVFR/VFR CEILINGS BECOME SCATTERED TO BROKEN BY
WEDNESDAY AFTERNOON. WINDS WILL REMAIN LIGHT.

&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$
SYNOPSIS.......SKOWRONSKI
SHORT TERM.....SKOWRONSKI
LONG TERM......TDH
AVIATION.......WOOD



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