000
FXUS63 KGRB 210439
AFDGRB

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GREEN BAY WI
1139 PM CDT SUN JUL 20 2014

UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE

.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 225 PM CDT SUN JUL 20 2014

DRY PERIOD EXPECTED. FRONTAL SYSTEM NOW OVER THE NORTHERN PLAINS
MOVES TOWARDS WESTERN LAKES TONIGHT...THOUGH STALLS/WEAKENS OVER
NORTHERN MN. NOT SEEING ANY FORCING THAT WILL OVERCOME CAP OF WARM
AIR OVER CWA. WHILE SBCAPE ON MONDAY AROUND 3K...CONVECTIVE TEMPS
RUNNING AROUND 96 WILL BE HARD TO REACH. HAVE PULLED POPS FROM
FORECAST FOR LATE TONIGHT WITH THOUGHTS ANYTHING THAT MATERIALIZES
WILL STAY WEST/NORTH OF CWA.

LESS CLOUD EXPECTED ON MONDAY WITH HEAT INDICES TO RUN IN LOWER
90S. WILL KEEP A MENTION IN THE HWO...ESPECIALLY SINCE WE HAVEN/T
HAD A REAL HOT/HUMID DAY YET THIS SUMMER.

SLY FLOW UP THE LENGTH OF LAKE MICHIGAN WILL LEAD TO MUCH COOLER
CONDITIONS ALONG THE LAKE. FOG/HAZE WILL RESTRICT VSBYS OVER THE
LAKE AS DEWS IN THE MID TO UPPER 60S MOVE IN. THE FOG COULD BRUSH
SHORELINE AREAS AT TIMES.

.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 225 PM CDT SUN JUL 20 2014

ZONAL FLOW AT 500MB EXPECTED AT THE START OF THE FORECAST PERIOD.
BY THE MIDDLE OF THE WEEK...RIDGE EXPECTED TO BUILD ACROSS THE
ROCKIES WITH A NORTHWEST FLOW DEVELOPING OVER THE REGION. ENERGY
MOVING ONSHORE THE PACIFIC NORTHWEST WEDNESDAY IS EXPECTED TO MOVE
INTO THE GREAT LAKES REGION NEXT WEEKEND. UPPER LOW IS EXPECTED TO
CLOSE OFF OVER THE WESTERN LAKES NEXT SUNDAY (JULY 27) AND MONDAY
(JULY 28). THIS FEATURE WOULD BRING BELOW NORMAL TEMPERATURES ALONG
WITH THE CHANCES FOR SHOWERS AND STORMS.

FOR MONDAY NIGHT...MCS ACTIVITY EXPECTED TO DEVELOP ACROSS
MINNESOTA. SOME OF THE MODELS DEPICT TWO AREAS OF HEAVIER
PRECIPITATION WHICH SEEMED REASONABLE BASED ON MODEL ANALYSIS. THE
FIRST AREA OF HEAVIER PRECIPITATION WOULD BE ACROSS NORTHERN
MINNESOTA WHICH WOULD RACE EAST/NORTHEAST AHEAD OF 500MB SHORTWAVE.
THE SECOND AREA OF HEAVIER PRECIPITATION WOULD BE IN RESPONSE TO LOW
LEVEL JET. THIS AREA OF STORMS IS EXPECTED TO DIVE SOUTH/SOUTHEAST
BASED ON 850/300MB THICKNESS PATTERN AND BETTER INSTABILITY.  SOME
OF THIS ACTIVITY COULD WORK INTO CENTRAL/NORTH-CENTRAL WISCONSIN
BY 12Z. WHAT HAPPENS ON TUESDAY IS STILL UP IN THE AREA DEPENDING
ON EVOLUTION OF THE OVERNIGHT CONVECTION. THERE IS STILL THE
POSSIBILITY SOME OF THE STORMS COULD BECOME STRONG OR SEVERE...BUT
IT IS NOT CLEAR CUT THAT WOULD HAPPEN TUESDAY AFTERNOON/EVENING IF
MORE STORMS WORK OVER THE ATMOSPHERE. HIGH TEMPERATURES ON TUESDAY
ALSO TRICKY DUE TO CONVECTION/CLOUD COVER.

CONTINUED CHANCES FOR SHOWERS AND STORMS TUESDAY EVENING...ALTHOUGH
TRIMMED OR REMOVED CHANCES ACROSS THE FAR NORTH. HIGH PRESSURE WILL
BRING MUCH COOLER AND LESS HUMID AIR WEDNESDAY THROUGH FRIDAY. LOWS
ACROSS THE FAR NORTH IN THE COLDER SPOTS COULD DIP INTO THE 40S
WEDNESDAY NIGHT AND THURSDAY NIGHT. THE NEXT CHANCE FOR SHOWERS AND
STORMS WOULD BE FRIDAY NIGHT INTO SATURDAY AHEAD OF APPROACHING
CLOSING UPPER LOW. UPPER LOW WILL BE CENTERED ACROSS NORTHEAST
WISCONSIN NEXT SUNDAY...BRINGING SHOWERS AND SCATTERED THUNDERSTORMS.
LATER SHIFTS MAY NEED TO LOWER MAXIMUM TEMPERATURES NEXT SUNDAY.
&&

.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1139 PM CDT SUN JUL 20 2014

SCATTERED TO BROKEN CLOUDS WITH BASES BETWEEN 3500
AND 6000 FEET WILL ARRIVE FROM WEST TO EAST OVERNIGHT AND CONTINUE
INTO PART OF MONDAY. THERE MAY BE A FEW HOURS OF MVFR FOG LATE
TONIGHT OR EARLY MONDAY. OTHERWISE VFR EXPECTED AT THE SURFACE.
LOW LEVEL WIND SHEAR MAY BE AN ISSUE FOR LIGHT AIRCRAFT OVERNIGHT
WITH SURFACE WINDS FROM THE SOUTH AROUND 5 KNOTS AND SOUTHWEST
WINDS AT 25 TO 30 KNOTS AROUND 1000 FT AGL.
&&

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

$$

SHORT TERM.....TE
LONG TERM......ECKBERG
AVIATION.......RDM