Severe Weather Thursday

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 TRENDS ARE BEING MONITORED FOR AN INCREASING SEVERE THREAT AND THE
POSSIBILITY OF AN ADDITIONAL WW ACROSS PARTS OF NORTH CENTRAL/
NORTHEAST IOWA...JUST TO THE SOUTH/WEST OF WWS 676/677.

A SIGNIFICANT SURFACE PRESSURE PERTURBATION PERSISTS WITH SMALL
SEVERE MESOSCALE CONVECTIVE SYSTEM NOW ADVANCING ACROSS/SOUTHEAST OF
THE LA CROSS AREA.  AND...DAMAGING WIND POTENTIAL APPEARS LIKELY TO
CONTINUE WITH ACTIVITY AS IT SPREADS ACROSS SOUTHWEST
WISCONSIN...TOWARD THE MADISON/LONE ROCK/PRAIRE DU CHIEN AREAS
BETWEEN NOW AND 22Z.  THEREAFTER...INGESTION OF MORE STABLE RAIN
COOLED AIR ON SOUTHEASTERLY SYSTEM RELATIVE INFLOW PROBABLY WILL
CONTRIBUTE TO WEAKENING CONVECTIVE TRENDS AND A DIMINISHING RISK FOR
DAMAGING WINDS AS THE GUST FRONT APPROACHES THE ILLINOIS/ WISCONSIN
BORDER.

POTENTIAL FOR VIGOROUS NEW DEVELOPMENT MAY THEN SHIFT TO STRONGER
LOW LEVEL WARM ADVECTION REGIME ALONG STALLING OUTFLOW BOUNDARY
UPSTREAM...ACROSS PARTS OF SOUTH CENTRAL/SOUTHEAST MN INTO NORTHEAST
IOWA.  DESPITE THE TENDENCY TOWARD WARMING MID-LEVELS ACROSS THIS
REGION...LATEST OBJECTIVE RUC ANALYSIS INDICATES THE BOUNDARY LAYER
REMAINS WEAKLY CAPPED...WITH MIXED LAYER CAPE OF 2000-3000 J/KG.  IN
THE PRESENCE OF MODERATELY STRONG DEEP LAYER SHEAR BENEATH 35-40 KT
WEST NORTHWESTERLY 500 MB FLOW... ADDITIONAL SUPERCELL STRUCTURES
CAPABLE OF PRODUCING LARGE HAIL/DAMAGING WINDS ARE POSSIBLE.

3:35pm = All warnings in our viewing area have been canceled for the time being.

(2:54:23 PM) iembot: DVN issues Tornado Warning for Whiteside [IL] till 3:45 PM CDT ...* AT 248 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A TORNADO 9 MILES NORTHWEST OF LOW MOOR...OR 14 MILES WEST OF CLINTON...MOVING SOUTHEAST AT 28 MPH.

(2:41:38 PM) iembot: DVN issues Severe Thunderstorm Warning for Carroll, Whiteside [IL] till 3:30 PM CDT

The cell just west of the Mississippi River is showing signs of some rotation and will have to be monitored closely in the near future.

(2:31:13 PM) iembot: LOT issues Severe Thunderstorm Warning for De Kalb, Lee [IL] till 3:30 PM CDT

(2:15:38 PM) iembot: LOT: 1 Ene Sublette [Lee Co, IL] public reports HAIL of nickel size (M0.88 INCH) at 02:13 PM CDT --

The cell that is located just south of Dubuque is quite strong as well and is moving slowly east at 25 mph. Once it reaches our viewing area, those counties will likely be warned upon. -ADAM

(1:48:56 PM) iembot: LOT: 7 W Amboy [Lee Co, IL] trained spotter reports TSTM WND GST of E60 MPH at 01:40 PM CDT --

(1:47:35 PM) iembot: LOT: 7 W Amboy [Lee Co, IL] trained spotter reports HAIL of nickel size (M0.88 INCH) at 01:40 PM CDT --

(1:42:27 PM) iembot: LOT: Walton [Lee Co, IL] public reports HAIL of golf ball size (M1.75 INCH) at 01:20 PM CDT --

(1:29:58 PM) iembot: LOT issues Severe Thunderstorm Warning for La Salle, Lee [IL] till 2:30 PM CDT

(1:17:20 PM) iembot: Storm Prediction Center issues SEVERE TSTM watch till 03:00 UTC (Watch Quickview)

(1:03:40 PM) iembot: DVN: Sterling [Whiteside Co, IL] trained spotter reports HAIL of pea size (E0.25 INCH) at 12:22 PM CDT --

(12:55:49 PM) iembot: Storm Prediction Center issues Mesoscale Discussion #1748 (View text)

(12:36:36 PM) iembot: LOT issues Severe Thunderstorm Warning for Lee, Ogle [IL] till 1:30 PM CDT

A few batches of thunderstorms have been making their way across Iowa this morning. They're somewhat scattered in nature and haven't been severe, but the Storm Prediction Center thinks that there may be enough energy for the storms to feed on that some may become marginally severe this afternoon. The primary threats would be gusty winds and hail.

The activity that's crossed the Mississippi in the past little while appears to be in a weakening state, as the amount of lightning has been dropping for the past hour or so. West of Dubuque, the storms have been increasing in intensity; in fact, a severe t'storm warning was just issued for one of the cells as I was finishing the previous sentence.