Nearcast data shows favorable conditions for convective initiation and maintenance through mid afternoon.  The first 2 images of nearcast at 19Z and 20Z show good theta-e values (yellows) at 780 mb (upper left) with a slightly cooler drier environment aloft (greens) at 500 mb (lower left).  Bright greens over central and eastern portions of JAX area support a favorable convective environment.   This analysis combined with soundings and other environment data are supportive of small hail with storms early this afternoon.

19Z:

20Z:

In the later 2 images below at 21Z and 22Z, the environment becomes less favorable for convection as we can see less of a threat of convection as the brighter yellows at 780 mb (upper left) begin to move off shore (a cold front enters the area).  Also at 500 mb (lower left), brighter yellows are observed moving into JAX central and eastern portions of the area indicating more warm/moist mid levels which would be less supportive of small hail and more supportive of heavy rainers given the environment conditions.  The theta-e difference (lower right) depicts most unstable/moist environment (bright greens) moving off shore as well.

21Z:

22Z:

AMS/Hovis

Around 1832z…cloud top cooling product showed strong cloud top cooling for two successive scans in the area of some showers moving across Berrien County in Southeast Georgia.  The showers  rapidly intensified with JAX composite reflectivity showing 55-60 dBZ by 1849z and 60-65 dBZ storm by 1904z.  Hovis/AMS

HRRR output painted the merging of the ongoing line of non-severe storms and new initiation ahead of this line.  CI and CTC showed an evidence of early convective initiation though lead time near 30 minutes.  nunez

Our EWP2012 debriefing today.  From my iPad.

Greg Stumpf, EWP2012 Week #1 Coordinator

MRMS echo tops data depicted signals associated with a t-storm with hail.  Strong signals are depicted at 0046Z at the 18 dbz and 30 dbz levels (lower left and lower right) with smaller signals noted at the 50 dbz and 60 dbz levels (upper left and upper right).  Although the signals at the 50 dbz and 60 dbz levels are small in area, they represent 50 dbz to 32 kft and 60 dbz to 26 kft which are significant levels for severe hail.

AMS

23Z GOES nearcast for 01Z supports strong updraft potential for the Brewster county storms.  Legacy Hail algorithm maintained 2 inch potential for a couple scans, so the potential for severe size hail is likely to continue.  This hail threat should continue through 03Z.  EMs and other decision makers should continue to monitor for potential warnings and statements.

Not a whole lot going on this evening.  However, 3D VAR (see image below) still depicting weak signals of updraft (upper left) and vorticity (lower left) with a garden variety t-storm west of Longfellow, TX (reflectivity in the upper right).

AMS