Severe Thunderstorm Warning 9, NWS Marquette, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MARQUETTE MI
1028 AM EDT SUN JUL 20 2003

A WEAK TROUGH CURRENTLY OVER THE CENTRAL UP...WITH A LOW
CURRENTLY JUST NE OF ESC. SOME THUNDERSTORMS HAVE DEVELOPED EAST OF
THE LOW...MOST LIKELY DUE TO H8 THETA-E ADVECTION AND MOISTURE FLUX
CVRG AHEAD OF THE LOW...AS WELL AS ENHANCE LOW LVL CVRG OVER THE
NEARSHORE WATERS OF EASTERN LAKE SUPERIOR. A WEAK S/WV OVER LK
SUPERIOR IS ALSO ENHANCING THIS CONVECTION THIS MORNING. EXPECT THE
S/WV TO MOVE EAST THIS MORNING...HOWEVER THE THUNDERSTORMS MAY HANG
AROUND NR THE SFC TROUGH FOR MOST OF THE DAY OVER THE SOUTHEAST.
OTHERWISE...EXPECT DNVA THIS MORNING AND EARLY THIS AFTN OVER THE
WEST AS WEAK S/WV RIDGING DEVELOPS AHEAD OF THE MAIN UPR S/WV
CURRENTLY OVER LAKE WINNIPEG. MAIN FCST CONCERNS THIS MORNING DEAL
WITH POPS THIS AFTN.

AM SOMEWHAT CONCERNED ABOUT POPS THIS AFTERNOON ESPECIALLY
N-CENTRAL/NW. THE 12Z RUC SHOWS NEGATIVE THETA-E ADVECTION FOR THE
REST OF THE AFTN WITH NEUTRAL TO SLIGHTLY NEGATIVE VORTICITY
ADVECTION. HOWEVER...MODIFIED RUC SOUNDINGS FOR 78/64 FOR LATE THIS
AFTN SHOWS NEARLY 1000 J/KG OF SBCAPE AND LI/S AROUND -7C AT IMT.
THE RUC ATTEMPTS TO SHOW THE SFC TROUGH STALLING OUT OVER THE S HALF
OF THE CWFA THIS AFTN...POSSIBLY ALLOWING FOR ENHANCED CVRG NR THE
BOUNDARY. HOWEVER THE BEST UPR ENERGY WILL NOT ARRIVE UNTIL LATE.
ONE COULD ARGUE THAT THERE WILL BE SOME JET SUPPORT LATE THIS
AFTERNOON OVER THE SOUTH WHICH MAY SERVE AS A FOCUS FOR
THUNDERSTORMS THIS AFTERNOON. THUS...HAVE OPTED TO KEEP CHC POPS
EAST AND FAR SOUTH TODAY. HOWEVER...WILL CUT POPS BACK TO SLIGHT
CHANCE NW AND N-CENTRAL. ULTIMATELY...IT LOOKS LIKE THE MAIN ENERGY
FROM THE MANITOBA S/WV WILL NOT AFFECT THE AREA UNTIL TONIGHT.

OTHERWISE...GOING TEMP FCST LOOKS GOOD. DESPITE NE FLOW...THE
SUNSHINE SHOULD ALLOW FOR TEMPS TO REACH THE MID-UPR 70S EVEN NEAR
THE SHORELINE SINCE NE FLOW IS PRETTY WEAK.

ZFP UPDATE OUT BY 1040 AM.

.MQT...NONE.

MRD

MIZ001>007-009>014-084-085-211200-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MARQUETTE MI
520 AM EDT SUN JUL 20 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL UPPER
MICHIGAN.

.DAY ONE...TODAY AND TONIGHT

ISOLATED THUNDERSTORMS ARE POSSIBLE EARLY THIS MORNING EAST OF A
HOUGHTON...IRON RIVER LINE. THERE IS ALSO A CHANCE OF THUNDERSTORMS
THIS AFTERNOON ACROSS ALL OF WEST AND CENTRAL UPPER MICHIGAN. THESE
STORMS WILL BECOME MORE NUMEROUS THIS EVENING AND CONTINUE OVERNIGHT.

.DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY

THERE IS A CHANCE OF THUNDERSTORMS ON FRIDAY AND SATURDAY.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION MAY BE NEEDED TONIGHT.

ADDITIONAL WEATHER INFORMATION MAY BE OBTAINED AT THE FOLLOWING URL:

HTTP://WWW.CRH.NOAA.GOV/MQT (ALL LOWER CASE)

DLG