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Mesoscale Discussion 101
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   Mesoscale Discussion 0101
   NWS Storm Prediction Center Norman OK
   0948 AM CST Tue Feb 12 2019

   Areas affected...central and eastern PA...northern NJ...central and
   eastern NY...CT...western MA and southern VT

   Concerning...Winter mixed precipitation 

   Valid 121548Z - 121945Z

   SUMMARY...A wintry precipitation mix will persist into the afternoon
   across the northeast states. Mostly freezing rain is expected from
   central to southeast PA with rates from .03 to locally .1 inch per
   hour. From southern NY to southeast NY and northern NJ, areas of
   moderate to heavy snow should transition to freezing rain toward
   noon or by early afternoon. Farther north from east central NY into
   northern CT, western MA and southern VT, areas of mostly moderate to
   heavy snow are expected.

   DISCUSSION...A large, mature winter storm is in progress over
   portions of the northeast states. Surface low will deepen over MI
   within zone of strong forcing for ascent accompanying a progressive
   shortwave trough. This process will result in a strengthening (60+
   kt) southerly low-level jet shifting northward through PA, NY and
   southern New England later this morning into the afternoon. The
   interaction of the low level jet with the east-west oriented
   baroclinic zone will augment isentropic ascent, promoting a
   continued northeast expansion of the precipitation area. Bands of
   moderate to heavy snow promoted by an increase in frontogenetic
   forcing will develop northeast with time through central and eastern
   NY. While farther south from southern NY, northeast PA into northern
   NJ and southern CT, increasing warm advection along low-level jet
   corridor will contribute to northward advance of the melting layer
   aloft, eventually resulting in a transition from snow to sleet and
   freezing rain. Precipitation should remain freezing rain across
   central and southern PA this morning.

   ..Dial.. 02/12/2019

   ...Please see for graphic product...


   LAT...LON   43337651 43877508 43347296 42367231 41587280 40847350
               40467412 40017589 39907687 40227828 41487942 42657827

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