Severe Thunderstorm Warning 29, NWS Gaylord, MI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE GAYLORD MI
1209 PM EDT THU JUN 29 2000

MAIN FORECAST CONCERN FOR ERN UPR/NRN LWR MI THIS AFTERNOON WILL BE
WITH THE THREAT/COVERAGE OF DIURNAL CONVECTION. CURRENTLY ON THE
REGIONAL SFC ANALYSIS...WELL-DEFINED TROUGH EXTENDS JUST EAST OF A
SAULT STE MARIE TO MANISTEE LINE. THE SFC TROUGH IS ASSOCIATED WITH
A RATHER VIGOROUS MID LEVEL SHORTWAVE DIVING SE ON THE BACK SIDE OF
THE MAIN HUDSON BAY VORTEX. Q-G FORCING (PDVA AND Q-VECTOR
CONVERGENCE) ALONG THE SFC...COMBINED WITH HIGH DEGREE OF SFC-500 MB
INSTABILITY...IS RESULTING IN WIDELY SCATTERED SHOWER/TSTM ACTIVITY
PER RECENT REGIONAL RADAR LOOPS.

Q-G FORCING QUICKLY BECOMES DOWNWARD THIS AFTERNOON BEHIND THE
SHORTWAVE AND THE NDVA AND SUBSIDENCE REGIME MOVES IN. AT THAT
POINT...FOCUSING MECHANISM FOR ORGANIZED CONVECTION WILL BE TOUGH TO
COME BY...THOUGH GIVEN THE LIGHT NORTHWESTERLY WIND FIELDS OFF THE
SFC AND ALOFT...SUSPECT LAKE BREEZE CONVERGENT BOUNDARIES ON THE
HURON SIDE MIGHT COME INTO PLAY LATER IN THE AFTERNOON. WORDED
ISOLATED SHOWERS/STORMS THROUGH EARLY AFTERNOON WEST OF I-75...
OTHERWISE KEPT THE MENTION IN THROUGH THE AFTERNOON EAST.

AS  FOR THE INSTABILITY PARAMETERS...MODIFIED 12Z KAPX OBSERVED AND
18Z MODEL SOUNDINGS SHOW CONVECTIVE TEMPS IN THE MID 60S (REAL LOW
FOR THIS TIME OF YEAR)...TOTAL TOTALS NEAR 50...AND LI'S AROUND -5C.
MODIFIED SOUNDINGS FOR A 69/52 TEMP/DWPT REGIME YIELDS POSITIVE
BUOYANCY AROUND 1500 J/KG. WEAK WIND FIELDS ALOFT (10-15 KTS MAX
THROUGH 500 MB) ALONG WITH FREEZING/WET BULB ZERO HEIGHTS OF
8200/7200 FT RESPECTIVELY WOULD SUGGEST THE LIKELIHOOD OF HAIL WITH
THE S^TRONGER THUNDERSTORMS. HOWEVER...NARROWNESS OF CAPE (LACK OF
UPDRAFT STRENGTH) ALONG WITH WET BULB ZERO TEMPS JUST BELOW 7500 FT
WOULD SUGGEST THE THREAT FOR LARGE HAIL IS UNLIKELY.

.APX...NONE..

HURLEY

MIZ008-015>036-041-042-301200-
SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE GAYLORD MI
1105 AM EDT THU JUN 29 2000

...SEVERE WEATHER OUTLOOK FOR NORTHERN LOWER AND EASTERN UPPER
MICHIGAN...

ISOLATED THUNDERSTORMS WILL AFFECT PORTIONS OF NORTHEAST LOWER
MICHIGAN THIS AFTERNOON. THESE STORMS ARE NOT EXPECTED TO BECOME
SEVERE...AND AS A RESULT SKYWARN SPOTTER ACTIVATION IS NOT
ANTICIPATED.

ISOLATED THUNDERSTORMS WILL DEVELOP ACROSS NORTHEAST LOWER MICHIGAN
BETWEEN 200 AND 600 PM...COINCIDING WITH PEAK DAYTIME HEATING. THE
AREA OF CONCERN WILL BE LOCATIONS EAST OF A CHEBOYGAN TO HOUGHTON
LAKE LINE. MOVEMENT OF THUNDERSTORMS WILL BE SOUTHEAST AROUND 15 MPH.

WHILE NOT EXPECTED TO BECOME SEVERE...ANY THUNDERSTORMS THAT DEVELOP
WILL BE CAPABLE OF HAIL UP TO A HALF INCH IN DIAMETER...ALONG WITH
WIND GUSTS TO 30 MPH AND LOCALLY HEAVY DOWNPOURS.

LISTEN TO NOAA WEATHER RADIO OR LOCAL RADIO OR TELEVISIION STATIONS
FOR THE LATEST INFORMATION.

HURLEY

MIZ008-015>036-041-042-300000-
SEVERE WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE GAYLORD MI
1117 AM EDT THU JUN 29 2000

...SEVERE WEATHER OUTLOOK FOR NORTHERN LOWER AND EASTERN UPPER
MICHIGAN...

ISOLATED THUNDERSTORMS WILL AFFECT PORTIONS OF EASTERN UPPER AND
NORTHERN LOWER MICHIGAN THIS AFTERNOON. THESE STORMS ARE NOT
EXPECTED TO BECOME SEVERE...AND AS A RESULT SKYWARN SPOTTER
ACTIVATION IS NOT ANTICIPATED.

ISOLATED THUNDERSTORMS WILL DEVELOP ACROSS EASTERN UPPER AND
NORTHERN LOWER MICHIGAN BETWEEN 200 AND 600 PM...COINCIDING WITH
PEAK DAYTIME HEATING. THE MAIN AREA OF CONCERN WILL BE LOCATIONS
ALONG AND EAST OF I-75. MOVEMENT OF THUNDERSTORMS WILL BE
SOUTHEAST AROUND 15 MPH.

WHILE NOT EXPECTED TO BECOME SEVERE...ANY THUNDERSTORMS THAT DEVELOP
WILL BE CAPABLE OF HAIL UP TO A HALF INCH IN DIAMETER...ALONG WITH
WIND GUSTS TO 30 MPH AND LOCALLY HEAVY DOWNPOURS.

LISTEN TO NOAA WEATHER RADIO OR LOCAL RADIO OR TELEVISION STATIONS
FOR THE LATEST INFORMATION.

HURLEY