Area Forecast Discussion
Issued by NWS Green Bay, WI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS63 KGRB 021144
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
644 AM CDT TUE SEP 2 2014

UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE

.SHORT TERM...TODAY...TONIGHT...AND WEDNESDAY
ISSUED AT 323 AM CDT TUE SEP 2 2014

PCPN TRENDS AND TEMPERATURES WILL BE THE MAIN FCST CONCERNS.

WV IMAGERY SHOWED A S/W TROF MOVG INTO SW MN/NW IA EARLY THIS
MORNING...AND PRODUCING SHRA/SCT TSTMS. IT APPEARS THAT THE BEST
DYNAMICS WITH THIS SYSTEM WILL MOVE ACROSS OUR SOUTHERN COUNTIES
LATE THIS MORNING AND EARLY AFTERNOON. WILL HAVE CHC POPS OVER
MOST OF THE CWA...WITH THE HIGHEST POPS SOUTH. WILL NEED TO
WATCH THE UPSTREAM RADARS AND SEE IF POPS NEED TO BE RAISED LATER
IN THE SHIFT. INSTABILITY MAY BE A BIT STRONGER THAN EARLIER
EXPECTED...AS MODIFIED SOUNDINGS INDICATE CAPE OF 1000-1500 J/KG...
SO HAVE INCREASED THE TSTM WORDING A BIT IN THE FCST. EXPECT
HIGHS IN THE 70S OVER THE ENTIRE FORECAST AREA.

ANY PCPN SHOULD TAPER OFF BY EVENING AS THE S/W TROF SHIFTS
EAST AND WEAK SURFACE RIDGING OCCURS. PARTLY CLOUDY SKIES AND
LIGHT WINDS WILL ALLOW MIN TEMPS TO DROP TO COMFORTABLE READINGS
IN THE 50S.

ON WEDNESDAY...MORNING SUNSHINE WILL GIVE WAY TO INCREASING
CLOUDS DURING THE AFTERNOON. A WARM FRONT IS EXPECTED TO SHIFT
INTO SOUTHERN MN AND SW WI...WITH A 30-40 KT LLJ AIMED AT WSTRN
WI. THE RRQ OF A JET STREAK WILL BE SITUATED OVER NC WI LATE IN
THE DAY...SO HAVE KEPT CHC POPS THERE DURING THE MID TO LATE
AFTERNOON. WAA WILL BOOST MAX TEMPS INTO THE UPPER 70S AND
LOWER 80S.

.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY
ISSUED AT 323 AM CDT TUE SEP 2 2014

MAIN CONCERN FOR THIS PERIOD WILL BE THE PROSPECTS OF STRONG OR
SEVERE STORMS AND LOCALLY HEAVY RAIN WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT. BY 00Z THURSDAY...40-45 KNOT 850MB JET WILL BE
FOCUSING CONVECTION ACROSS THE UPPER GREAT LAKES REGION. STILL
SOME UNCERTAINTY IN WHERE COMPLEX WILL FORM...BUT IT APPEARS
NORTH-CENTRAL AND NORTHEAST WISCONSIN WILL LIKELY SEE LOCALLY
HEAVY RAIN AS 850MB JET VEERS DURING THE NIGHT. WRF MODEL
INDICATING 35 TO 50 KNOTS OF 0-6 KM SHEAR AND 700-900 J/KG OF
DOWNDRAFT CAPE. COULD NOT RULE OUT SEVERE STORMS WITH THESE TYPE
OF PARAMETERS...ESPECIALLY ACROSS CENTRAL AND NORTH-CENTRAL
WISCONSIN. IF STORMS ORGANIZE...COULD BE A LATE NIGHT WIND EVENT
FOR SOME LOCATIONS ACROSS THE REGION.

ANY ONGOING ACTIVITY SHOULD WANE OR END THURSDAY MORNING. STORM
FORMATION MORE COMPLEX LATER THURSDAY. MODEL SOUNDINGS INDICATED
DECENT CAP ACROSS EASTERN WISCONSIN...THUS MAY NEED TO WAIT FOR
CONVECTION TO FIRE ALONG AND JUST BEHIND THE COLD FRONT. HAVE
LOWERED RAIN CHANCES ACROSS THE EAST DUE TO CAPPING ISSUES...BUT
CONTINUED HIGH CHANCE POPS ACROSS THE NORTH DUE TO PROXIMITY OF
COLD FRONT LATE THURSDAY AFTERNOON. FRONT WILL CROSS THE AREA
THURSDAY NIGHT. THE TIMING OF THE FRONT IS NOT THE GREATEST...BUT
IT HAS A LOT WORKING FOR IT FOR INITIATION OF SEVERE STORMS. REGION
WILL BE IN THE RIGHT ENTRANCE REGION OF A 100 KNOT 250 JET STREAK.
CAPES OF 2500 TO 3500 J/KG ARE ANTICIPATED THURSDAY AFTERNOON...
THUS ONCE STORMS BREAK THE CAP THEY SHOULD BECOME STRONG OR SEVERE
FAIRLY QUICKLY. 0-6KM SHEAR OF 30-45 KNOTS VERY FAVORABLE FOR
SEVERE STORMS. PRECIPITABLE WATER VALUES SHOULD BE 150-200 PERCENT
OF NORMAL TO SUPPORT HEAVY/TORR ENTAIL RAINS WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT.

LINGERED A CHANCE OF SHOWERS FRIDAY MORNING ACROSS THE EAST...THEN
HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN FRIDAY AFTERNOON
THROUGH THE WEEKEND. NEXT CHANCE FOR RAIN WILL BE EARLY NEXT WEEK.
MINOR CHANGES MADE TO THE EXTENDED MAX/MIN TEMPERATURES...ADJUSTING
FOR OUR LOCAL BIASES.
&&

.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 640 AM CDT TUE SEP 2 2014

PATCHY FOG WILL QUICKLY DISSIPATE EARLY THIS MORNING. AN UPPER
LEVEL DISTURBANCE WILL BRING SCT SHRA/TSRA TODAY. CONFIDENCE IS
NOT HIGH ENOUGH TO MENTION TSTMS IN THE TAFS...SO ONLY MENTIONED
SHOWERS FOR NOW. ASIDE FROM BRIEF VSBY REDUCTION WITH STORMS...
CONDITIONS SHOULD BE MAINLY VFR. CLEARING SKIES ARE EXPECTED DURING
THE MID TO LATE AFTERNOON.

&&

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

$$

SHORT TERM.....KIECKBUSCH
LONG TERM......ECKBERG
AVIATION.......KIECKBUSCH






USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.