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 160321
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1021 PM CDT WED APR 15 2015

UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE

.SYNOPSIS...
ISSUED AT 253 PM CDT WED APR 15 2015

CONTINUED MILD AND DRY INTO THE WEEKEND...THEN TURNING SHOWERY AND
MUCH COOLER LATE IN THE WEEKEND AND NEXT WEEK.

THE LARGE SCALE PATTERN ARCS WESTERN AND CENTRAL NOAM IS SPLIT. A
VERY HIGHLY AMPLIFIED SRN STREAM IS ACRS THE CONUS...WITH A
FLATTER NRN STREAM ACRS CANADA. THE SRN STREAM UPR TROF OVER THE
INTERMOUNTAIN WEST WL NEARLY CUT-OFF THE NEXT SEVERAL DAYS. BUT THE
SEPARATE STREAMS WILL BEGIN TO PHASE BACK TOGETHER BY LATE IN THE
WEEKEND...AS THE WRN TROF BEGINS TO PROGRESS EWD INTO THE RGN. THE
TREND NEXT WEEK WL BE FOR CONTINUED CONSOLIDATION/AMPLIFICATION...WITH
SHARP RIDGE SETTING UP OVER THE INTERMOUNTAIN WEST AND A FAIRLY
DEEP TROF FM WRN HUDSON BAY TO THE GREAT LAKES RGN.

TEMPERATURES WILL REMAIN ABOVE SEASONAL NORMALS THE NEXT FEW
DAYS...THEN DROP BACK TO A LITTLE BELOW NORMAL BY EARLY NEXT WEEK.
THE MAIN CHANCE FOR PRECIPITATION WILL BE WITH THE SYSTEM ARRIVING
IN THE AREA LATE IN THE WEEKEND AND LINGERING INTO EARLY NEXT
WEEK. THE BEST GUESS IS FOR PRECIPITATION AMOUNTS TO END UP NEAR
NORMAL FOR THE PERIOD.
&&

.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 253 PM CDT WED APR 15 2015

MAIN CONCERNS...FIRE WEATHER THIS EVENING...AND WHETHER TO
INCLUDE RAIN CHANCES IN THE EAST ON THURSDAY.

DRY EAST/SOUTHEAST FLOW ACROSS THE AREA TODAY...AROUND A HIGH
PRESSURE SYSTEM IN CANADA...ALLOWED DEW POINTS TO FALL INTO THE
TEENS TO LOWER 20S. THE COLD WATERS OF LAKE MICHIGAN AND GREEN
BAY KEPT TEMPERATURES MAINLY THE 50S ACROSS THE EASTERN PART OF THE
FORECAST AREA BUT LOCATIONS FARTHER INLAND REACHED THE LOWER AND
MIDDLE 60S. RELATIVE HUMIDITIES WERE MOSTLY IN THE 10 TO 20
PERCENT RANGE AWAY FROM THE LAKE AND BAY.

THE SURFACE PRESSURE GRADIENT SHOULD WEAKEN THIS EVENING AND
OVERNIGHT AS THE HIGH MOVES TO NEAR NEW YORK CITY BY 12Z. EXPECT
TEMPERATURES TO FALL QUICKLY ONCE THE SUN HAS SET AND WINDS BECOME
LIGHT. THIS WILL RESULT IN A RAPID INCREASE IN HUMIDITIES THAT
SHOULD IMPROVE FIRE WEATHER CONDITIONS.

DEW POINTS ACROSS FAR SOUTHEAST WISCONSIN WERE IN THE LOWER 30S
THIS AFTERNOON AND MOS GUIDANCE FROM 12Z GFS AND 12Z NAM INDICATED
INCREASING DEW POINTS IN THE FORECAST AREA OVERNIGHT AND ON
THURSDAY...AS WELL AS SOME CHANCE POPS FOR MTW. POPS WERE
ASSOCIATED WITH A WEAK SURFACE LOW/TROUGH...A MID LEVEL SHORT WAVE
AND INCREASING LOW LEVEL MOISTURE IN RETURN FLOW AROUND THE HIGH. THE
12Z NAM BROUGHT QPF INTO THE SOUTHERN PARTS OF CALUMET AND MANITOWOC
COUNTIES WHILE THE 12Z GFS/ECMWF /GEM-NH ALL HAD QPF CLOSE TO THE
SHORE BUT REMAINING OVER LAKE MICHIGAN. HAVE LEFT OUT ANY MENTION
OF RAIN AT THIS POINT SINCE 12Z SOUNDINGS AT GRB AND ILX WERE SO
DRY...WITH PWATS IN THE 0.18 TO 0.28 RANGE. THE 12Z OHX SOUNDING
HAD A PWAT OF 1.28 INCHES SO HOPEFUL MY STRATEGY DOES NOT BACKFIRE.

.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 253 PM CDT WED APR 15 2015

TAIL OF NRN STREAM SHRTWV WL BRUSH THE AREA FRIDAY NIGHT...HELPING
TO PUSH A WK COLD FRONT SOUTH THOUGH THE AREA. MOISTURE WL REMAIN
LIMITED...SO CHANCES ARE THE FRONT WILL COME THROUGH DRY.

HIGH PRESSURE PASSING EAST OF THE AREA WL BRING A LITTLE COOLER
CONDITIONS FOR THE START OF THE WEEKEND. THEN SHRTWV ENERGY
EJECTING OUT AHEAD OF APPROACHING SRN STREAM SRN STREAM SYSTEM WL
BEGIN REACHING THE AREA SUNDAY. AS TYPICAL...SOME QUESTIONS ON
TIMING OF THE ARRIVAL OF PCPN WITH THE SRN STREAM SYSTEM. EXTENDED
FCST INITIALIZATION GRIDS DID NOT TAKE POPS BEYOND CHC CATEGORY.
THAT/S GOOD ENOUGH FOR NOW...THOUGH SYSTEM LOOKS TO BE A GOOD
ENOUGH PRECIP PRODUCER THAT WE/LL EVENTUALLY NEED LIKELY OR
CATEGORICAL POPS ONCE WE CAN HONE IN ON TIMING A LITTLE BETTER.

MUCH COOLER AND SHOWERY CONDITIONS WILL LINGER INTO EARLY NEXT
WEEK AS UPR TROF SETTLES INTO THE REGION.



SKOWRONSKI.
&&

.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1021 PM CDT WED APR 15 2015

VFR CONDITIONS EXPECTED TONIGHT INTO THURSDAY. LIGHT EAST WIND AT
THE SURFACE WILL PREVAIL TONIGHT INTO THURSDAY BEFORE TURNING
VARIABLE OVER CENTRAL AND NORTH CENTRAL WISCONSIN WITH A WEAK
FRONTAL BOUNDARY.  A WEAK DISTURBANCE WILL SLIDE OVER SOUTHEAST
WISCONSIN LATER TONIGHT INTO THURSDAY MORNING. A FEW SPRINKLES BUT
MORE THAN LIKELY VIRGA MAY FALL FROM A MID LEVEL DECK OF CLOUDS
OVER EAST CENTRAL WISCONSIN TOWARD THURSDAY MORNING.
&&

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

$$

SYNOPSIS.......SKOWRONSKI
SHORT TERM.....MG
LONG TERM......SKOWRONSKI
AVIATION.......TDH





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