MD for NE NEBR, N. IA, S. MN, and W. WI!

[Guest]

503
ACUS11 KWNS 161951
SWOMCD
SPC MCD 161951
WIZ000-IAZ000-MNZ000-NEZ000-SDZ000-162145-

MESOSCALE DISCUSSION 0353
NWS STORM PREDICTION CENTER NORMAN OK
0251 PM CDT FRI APR 16 2004

AREAS AFFECTED...NERN NEB / NRN IA / SRN MN / WRN WI

CONCERNING...SEVERE THUNDERSTORM POTENTIAL

VALID 161951Z - 162145Z

CONVECTION IS INCREASING ALONG WARM FRONT FROM E CENTRAL NEB NEWD
INTO WRN MN. DESPITE RELATIVELY DRY LOW LEVELS...EXPECT ISOLATED
THUNDERSTORMS TO DEVELOP WITH LOCALLY DAMAGING WINDS POSSIBLE. WW
MAY BE REQUIRED.

DEEP BOUNDARY LAYER IS INDICATED ACROSS THE REGION ALONG WARM
FRONT...WHERE DEWPOINTS ARE GENERALLY IN THE MID 40S. DESPITE
RELATIVELY DRY LOW LEVELS...STEEP LAPSE RATES ARE CONTRIBUTING TO
500 TO 1500 J/KG HIGH-BASED CAPE OVER THIS AREA. ALTHOUGH STORMS
SHOULD REMAIN GENERALLY ISOLATED / CONFINED TO THE IMMEDIATE FRONTAL
ZONE OVER THE NEXT FEW HOURS...WLY MID-LEVEL FLOW NEAR 50 KT IS
CONTRIBUTING TO SUFFICIENT DEEP-LAYER SHEAR FOR STORM ORGANIZATION.
DEEP BOUNDARY LAYER SUPPORTS A THREAT FOR LOCALLY DAMAGING
DOWNBURSTS WITH STRONGER CELLS...AND WW MAY BE REQUIRED IF IT
APPEARS THAT STORM COVERAGE WILL BECOME SUFFICIENT TO WARRANT MORE
THAN JUST A LIMITED / LOCAL THREAT.

..GOSS.. 04/16/2004

PLEASE SEE http://WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...ARX...MPX...DMX...FSD...OAX...GID...LBF...

44449314 44969094 43299042 41089667 40969833 41669861
42989632

[Guest]

871
WWUS20 KWNS 162046
SEL5
SPC WW 162045
IAZ000-170300-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 75
NWS STORM PREDICTION CENTER NORMAN OK
345 PM CDT FRI APR 16 2004


THE NWS STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF


CENTRAL AND EASTERN IOWA


EFFECTIVE THIS FRIDAY AFTERNOON AND EVENING FROM 345 PM UNTIL 1000
PM CDT.


HAIL TO 1.5 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.


THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 85 STATUTE MILES
EAST AND WEST OF A LINE FROM 40 MILES WEST OF DES MOINES IOWA TO
20 MILES NORTH NORTHEAST OF MASON CITY IOWA.


REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA.
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS. SEVERE THUNDERSTORMS CAN AND OCCASIONALLY DO PRODUCE
TORNADOES.


DISCUSSION...CONVECTION IS BEGINNING TO INTENSIFY ALONG BOUNDARY
ACROSS NWRN IA. THIS ACTIVITY IS EXPECTED TO INCREASE IN AREAL
COVERAGE AND ORGANIZATION WITH A POSSIBLE MCS EXPECTED BY EARLY
EVENING. VERY STEEP LAPSE RATES WILL SUPPORT DAMAGING WIND
THREAT...ESPECIALLY IF MCS DEVELOPS AS EXPECTED.


AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1.5 INCHES. EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60
KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 400. MEAN STORM
MOTION VECTOR 26025.


...DARROW/EVANS


;413,0960 432,0945 432,0912 413,0924;