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000
FXUS63 KGRB 230849
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
349 AM CDT THU MAY 23 2013

FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SYNOPSIS...
ISSUED AT 342 AM CDT THU MAY 23 2013

HIGHLY AMPLIFIED UPR PATTERN IN PLACE OVER THE CONUS...AND WL
REMAIN SO THROUGHOUT THE PERIOD. THE MOST PERSISTENT FEATURE WL
BE UPR LOW OVER THE PAC NW. DOWNSTREAM...UPR TROF NOW CROSSING THE
GREAT LAKES RGN WL SETTLE OVER NEW ENGLAND THROUGH THE HOLIDAY
WEEKEND BEFORE SHIFTG E NEXT WEEK. A SHARP/SOMEWHAT BLOCK UPR
RIDGE WL PERSIST BTWN THE 2 TROFS...AND EXTEND FM THE PLAINS NWD
INTO THE CANADIAN PRAIRIE PROVINCES.

NWLY UPR FLOW DOWN THE PLAINS RIDGE AND INTO THE ERN TROF WL BRING
A SURGE OF CHILLY CANADIAN AIR SWD...RESULTING IN MUCH BLO NORMAL
TEMPS FOR THE START OF THE FCST PERIOD. BUT TEMPS SHOULD TREND
UPWARD...AND BE ABV NORMAL BY THE MIDDLE OF NEXT WK. THE NEXT CHC
FOR SIG PCPN PROBABLY WON/T COME UNTIL THE MIDDLE OF NEXT WK.
&&

.SHORT TERM...TODAY...TONIGHT...AND FRIDAY
ISSUED AT 342 AM CDT THU MAY 23 2013

RENMANTS OF PCPN BAND IN UPR DEFORMATION ZONE WEAKENING AS THEY
SWING BACK SE ACRS THE AREA EARLY THIS MORNING. PCPN SHOULD EXIT
THE E THIS MORNING. CLDS WL LINGER FOR A LITTLE WHILE AFTER THE
PCPN ENDS...BUT THERE IS A SHARP CLEARING LINE WORKING SEWD ACRS
MN/LAKE SUPERIOR...AND IT SHOULD BEING OVERSPREADING THE FCST AREA
ARND DAYBREAK. NEED TO KEEP AN EYE ON A RATHER SOLID-LOOKING SC
DECK WAS THAT WAS SURGING SWWD FM SE ONTARIO. BUT STG SUBSIDENCE
IS EXPECTED ACRS THE AREA TDA IN THE WAKE OF NRN SHRTWV THAT WAS
DIGGING SWD AND PHASING WITH UPR TROF CROSSING THE RGN. SO EXPECT
PLENTY OF SUNSHINE ACRS THE AREA. DESPITE THAT...RATHER STRONG N
WINDS WL KEEP TEMPS 10-15F DEG BLO NORMAL.

SFC HIGH WL RIDGE INTO THE AREA THIS EVENING...AND EXPAND ACRS
THE AREA OVERNIGHT. THE COMBINATION OF CLEAR SKIES...COOL DRY
AIR...AND DIMINISHING WINDS WL ALLOW TEMPS TO REACH UNSEASONABLY
COLD LEVELS. WENT AOB GUID FOR MINS MOST AREAS. WL UPGRADE THE
FREEZE WATCH TO A WARNING AND POST A FROST ADVISORY FOR THE REST
OF THE AREA. SOME CONCERN WE COULD KEEP JUST ENOUGH WIND IN THE
FAR E TO HOLD TEMPS UP A BIT AND PREVENT FROST. BUT GIVEN HOW
LATE WE ARE INTO THE SPRING...DECIDED TO ERR ON THE SIDE OF
CAUTION AND POST ADVSIORY EVEN WHERE FROST ISN/T A CERTAINTY. WL
DETAIL THE UNCERTAINTY IN THE NPW PRODUCT.

THE WARMING TREND WL START FRI AS THE HIGH SHIFTS OFF TO THE E.
EVEN THOUGH THERE WL BE AN ELY FLOW ON THE BACK SIDE OF THE
DEPARTING HIGH...WINDS WL BE RELATIVELY LIGHT...AND MOST GUID
MAXES SEEMED TOO COOL...ESP OVER E-C WI.

.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 342 AM CDT THU MAY 23 2013

HIGH PRESSURE IS EXPECTED TO DOMINATE THE WEATHER PATTERN
THROUGHOUT THE MEMORIAL DAY WEEKEND. FOR FRIDAY NIGHT...SHOWERS
AND STORMS ACROSS THE PLAINS WILL MOVE INTO WESTERN WISCONSIN
AFTER MIDNIGHT. THE SHOWERS AND STORMS WILL WEAKEN AND DIMINISH IN
AREAL COVERAGE AS THE BAND OF PRECIPITATION MOVES INTO THE RIDGE.
NEW ECMWF DOES PRODUCE A FEW HUNDREDTHS OF AN INCH ACROSS OUR FAR
SOUTHWEST LATE FRIDAY NIGHT/SATURDAY MORNING. THINK THIS IS
OVERDONE. THINKING THERE WOULD BE A FEW SPRINKLES SATURDAY MORNING
OVER OUR FAR SOUTHWEST COUNTIES. MODELS CONTINUE TO WAVER ON
PRECIPITATION FOR SATURDAY NIGHT INTO MEMORIAL DAY. THE GFS/WRF
HAVE BEEN THE MOST INCONSISTENT IF PRECIPITATION WOULD WORK INTO
THE AREA. REALLY LIKE THE ECMWF SOLUTION SINCE IT HAS BEEN THE
MOST CONSISTENT AND THE 00Z CANADIAN HAS FOLLOWED THIS TREND.
THINK MUCH OF SUNDAY AND MEMORIAL DAY WILL BE DRY. DID KEEP A
TOKEN 20 POP ACROSS OUR SOUTHWEST JUST IN CASE PRECIPITATION
SHOULD SLIP INTO OUR AREA DURING THIS TIME FRAME. ONLY WENT WITH
SHOWERS AS PRECIPITATION WILL BE HEADING INTO A DRY AND STABLE AIR
MASS.

ATTENTION THEN TURNS TO TUESDAY INTO THE WEDNESDAY NIGHT PERIOD.
A SHIFT IN THE PATTERN WILL BRING MUCH WARMER AND MORE HUMID
CONDITIONS BY THURSDAY. SOME QUESTION ON THE TIMING OF THE MAIN
WARM FRONT...BUT THINK MOST ACTIVE PERIOD FOR THUNDERSTORMS WOULD
BE ON WEDNESDAY INTO WEDNESDAY NIGHT. TEMPERATURES NEXT THURSDAY
COULD BE WELL INTO THE 80S WITH DEW POINTS APPROACHING 70. IT IS
TOO EARLY TO DETERMINE IF ANY OF THE STORMS WOULD BECOME SEVERE
WEDNESDAY/WEDNESDAY NIGHT AS THE MAIN WARM FRONT MOVES THROUGH THE
AREA.

BASED ON SURFACE RIDGE REMAINING ACROSS THE WESTERN LAKES THROUGH
THE WEEKEND...LOWERED MIN TEMPERATURES A FEW DEGREES FRIDAY NIGHT
AND SATURDAY NIGHT ACROSS THE NORTH/NORTHEAST DUE TO LESS CLOUD
COVER AND DRY AIR MASS IN PLACE. FROST IS AGAIN POSSIBLE FRIDAY
NIGHT NORTH OF A MERRILL TO MARINETTE LINE. COLDEST TEMPERATURES
OVER THE MEMORIAL DAY WEEKEND WILL BE TOWARDS IRON MOUNTAIN AREA
WITH READINGS SLIGHTLY WARMER TOWARDS TOMAHAWK AND MERRILL. MIN
TEMPERATURES ON MEMORIAL DAY MAY NEED TO BE LOWERED IN LATER
FORECASTS DUE TO THE PERSISTENT RIDGE OVER THE WESTERN LAKES.
&&

.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 342 AM CDT THU MAY 23 2013

ONCE LOW CLDS EXIT THE AREA THIS MORNING...VFR CONDITIONS EXPECTED
FOR THE NEXT SEVERAL DAYS.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY FROM MIDNIGHT TONIGHT TO 7 AM CDT FRIDAY FOR
WIZ020-022-030-031-035>040-045-048>050-073-074.

FREEZE WARNING FROM MIDNIGHT TONIGHT TO 7 AM CDT FRIDAY FOR
WIZ005-010>013-018-019-021.
&&

$$

SYNOPSIS.......SKOWRONSKI
SHORT TERM.....SKOWRONSKI
LONG TERM......ECKBERG
AVIATION.......SKOWRONSKI