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 040832
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
332 AM CDT SAT JUL 4 2015

FORECAST DISCUSSION FOR ROUTINE MORNING FORECAST ISSUANCE

.SYNOPSIS...
ISSUED AT 328 AM CDT SAT JUL 4 2015

SEASONABLY WARM TEMPERATURES FOR THE REMAINDER OF THE INDEPENDENCE
DAY WEEKEND. SOME ISOLATED THUNDERSTORMS ARE POSSIBLE THIS
AFTERNOON...MAINLY IN CENTRAL WISCONSIN...OTHERWISE THE REST OF
THE WEEKEND LOOKS TO BE RAIN FREE.

THE UPR FLOW ACRS NOAM IS IN THE PROCESS OF READJUSTING TO THE WWD
SHIFT OF AN UPR ANTICYCLONE INTO THE GULF OF AK REGION. THE NEW
PATTERN WL FEATURE AN UPR TROF OVER CENTRAL CANADA. TO THE
SOUTH...A SEASONABLY STG BAND OF WESTERLIES WL SET UP ACRS SRN
CANADA AND THE NRN CONUS. THE PATTERN WL RESULT IN TEMPERATURES
OSCILLATING BETWEEN MODESTLY ABOVE AND BELOW NORMAL. READINGS WL
START OUT ABOVE NORMAL...COOL TO BELOW NORMAL FOR THE MIDDLE OF
NEXT WEEK...THEN WARM AGAIN LATE IN THE WEEK. PRECIPITATION
AMOUNTS WL PRIMARILY COME DOWN TO WHAT OCCURS WITH FRONTAL SYSTEM
CROSSING THE AREA EARLY NEXT WEEK...AND THAT LOOKS LIKE A FAIRLY
GOOD PRECIP PRODUCER AT THIS POINT. THERE COULD ALSO BE ADDITIONAL
PRECIPITATION LATE IN THE PERIOD...SO AMNTS FOR THE PERIOD WL
PROBABLY END UP AOA NORMAL.
&&

.SHORT TERM...TODAY...TONIGHT...AND SUNDAY
ISSUED AT 328 AM CDT SAT JUL 4 2015

OVERALL...A PRETTY QUIET SHORT-TERM PERIOD...BUT WITH A FEW ITEMS
OF CONCERN. FOG HAD BECOME PRETTY WIDESPREAD ACRS N-C WI EARLY
THIS MORNING...MAINLY IN AREAS BEHIND WK FRONTAL BOUNDARY SAGGING
SWD ACRS THE AREA. A FEW OBS HAD VSBYS BLO 1/4SM...SO IT COULD
HAVE AN IMPACT ON TRAVEL. PLAN TO HANDLE WITH SPS UNLESS THINGS
TAKE A SHARP TURN FOR THE WORSE.

NWLY FLOW ALOFT WL LIKELY CONTINUE TO PUSH THE BOUNDARY SWD. IT
SHOULD STRETCH OUT PARALLEL TO THE MID/UPR FLOW AND EXTEND FM
NEAR DLH TO MKE BY MID-AFTN. MODEL FCST SOUNDINGS SUGGEST SOME
INSTABILITY IN THE MOISTURE POOLING NR THE BOUNDARY...THOUGH TEMPS
ALOFT APPEAR ALMOST WARM ENOUGH TO PROVIDE A CAP. CONVERGENCE WL
ALSO BE LIMITED BY GENERALLY WK WIND FIELDS...AND UPR SUPPORT
LACKING. ANTICIPATE GETTING ISOLD SHRA/TSRA TO DEVELOP INVOF THE
FRONT THIS AFTN...SO CARRIED SLGT CHC POPS MAINLY IN CENTRAL WI.

THE FRONT WL START BACK N TNGT AS LARGE SCALE SLY FLOW BEGINS TO
STRENGTHEN. FRONT SHOULD BE N OF THE AREA BY SUN AFTN. GIVEN MODEL
FCST SOUNDING SHOW CONTD WARMING IN THE 800-700 MB LAYER...
CONVECTION SEEMS UNLIKELY. STUCK WITH DRY FCST.

NO SIG CHGS TO TEMPS FM PREV FCST.

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY
ISSUED AT 328 AM CDT SAT JUL 4 2015

THE LATEST GFS ENSEMBLE MEAN INDICATES BROAD TROUGHING WILL EXIST
OVER THE NORTHERN PLAINS AND WESTERN GREAT LAKES THROUGH MUCH OF THE
NEXT WORK WEEK...FOLLOWING THE SHORTWAVE MOVING THROUGH MONDAY INTO
MONDAY NIGHT.  STILL SOME TIMING DIFFERENCES WITH THIS SHORTWAVE AND
THE ASSOCIATED FRONT MOVING ACROSS THE REGION EARLY NEXT WEEK.  THE
ECMWF AND SREF APPEAR TO LINE UP THE BEST WITH THE LATEST ENSEMBLE
GUIDANCE...SO WILL USE THEIR SOLUTIONS FOR THE DETAILS.
THEREAFTER...A BLEND OF THE ECMWF AND GFS ENSEMBLE MEAN WILL SUFFICE.

SUNDAY NIGHT THROUGH MONDAY NIGHT...THE NIGHT WILL START OUT MOSTLY
CLEAR AND WARM WITH A PERSISTENT SOUTHERLY BREEZE.  CLOUDS WILL BE
ON THE INCREASE LATE WHEN A STRONG COLD FRONT PUSHES ACROSS THE
NORTHERN MISSISSIPPI VALLEY. A CHANCE OF SHOWERS AND STORMS WILL
SPREAD INTO WESTERN VILAS AND ONEIDA COUNTIES LATE.  THE FRONT WILL
CONTINUE TO MARCH EAST INTO WESTERN WI BY EARLY AFTERNOON AND
CENTRAL WI BY EARLY MONDAY EVENING.  QG FORCING AND MID-LEVEL FGEN
WILL INCREASE AS THE FRONT DRAWS CLOSER...WHILE SOUTHWEST WINDS WILL
ADVECT PWATS APPROACHING 2.0 INCHES INTO THE REGION.  THOUGH FORCING
AND MOISTURE WILL BE PLENTIFUL...INSTABILITY IS UNCERTAIN PENDING
TIMING.  IF THE TIMING IS SLOWER LIKE THE SREF AND ECMWF
SHOW...SUFFICIENT HEATING OVER CENTRAL AND NORTHEAST WI COULD RISE
ML CAPES INTO THE 750-1000 J/KG RANGE.  0-6KM BULK SHEAR VALUES
COULD ALSO IMPROVE TO AROUND 30 KTS ALONG THE FRONT.  SO IT STILL
LOOKS LIKE AT LEAST A LOW END SEVERE THREAT IS POSSIBLE MONDAY
AFTERNOON INTO THE EVENING FROM CENTRAL INTO NORTHEAST WI.  LOCALLY
HEAVY RAINFALL IS ALSO A DISTINCT POSSIBILITY GIVEN THE SLOW MOVING
FRONT AND MOISTURE-LADEN AIR.  THE FRONT WILL BE EXITING EASTERN WI
LATE MONDAY EVENING OR OVERNIGHT ENDING THE THUNDERSTORM THREAT.
COOLER AND DRIER AIR WILL INVADE WESTERN SECTIONS OF THE FORECAST
AREA DURING THE NIGHT.

REST OF THE FORECAST...HIGH PRESSURE WILL THEN BUILD INTO THE REGION
ON TUESDAY AND HANG AROUND THROUGH THURSDAY.  CONDITIONS START TO
BECOME MORE UNSETTLED BY FRIDAY OR NEXT SATURDAY AS UPPER FLOW
BECOMES SOUTHWEST.
&&

.AVIATION...FOR 12Z TAF ISSUANCE
ISSUED AT 328 AM CDT SAT JUL 4 2015

FOG OVER THE W SHOULD LIFT BY MID-MORNING. SOME QUESTION ABOUT
VSBYS LATER TDA SINCE SMOKE FM CANADIAN FIRES REDUCED VSBYS IN
SOME AREAS YDA. HARD TO GAUGE WHETHER OR NOT THAT WL HAPPEN AGAIN
TDA...BUT DO NOT ANTICIPATE TAKING VSBYS BLO MVFR AT THIS POINT.
&&

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

$$

SYNOPSIS.......SKOWRONSKI
SHORT TERM.....SKOWRONSKI
LONG TERM......MPC
AVIATION.......SKOWRONSKI



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