Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Jacksonville Florida
259 PM EDT sun Apr 26 2015
Short term /through Monday night/...
much less activity this afternoon than Saturday afternoon...as a
cold front works back to the south. Weak middle level impulses in SW
flow continue to cross central Florida...with a few showers just
south of Marion/Flagler counties this afternoon. With intense heating
and some potential for small scale boundaries clipping northern
Florida...will keep isolated to widely scattered probability of precipitation late this
afternoon from jax south. With some deep layer shear a storm or two
could become strong. Any activity early this evening will diminish
after sunset. A little stronger impulse is prognosticated to move onshore
from the Gulf overnight/early Monday...and will include low end
scattered probability of precipitation for north central Florida late. Lows of 65 to 70 will
Monday/Monday night...the cold front is expected to enter north
central Florida Monday then stall. With some middle level forcing north of
the boundary...will continue to use scattered probability of precipitation Monday afternoon
across north central Florida...with leaser coverage for NE Florida and
extreme southeast Georgia. Do not expect strong/severe storms as the area will
be on the more stable cool sector. Low level northeast flow will
lead to a substantially cooler day...with highs in the 70s along
the coast...and mainly lower 80s inland. Will maintain chance probability of precipitation
for Monday night S of Florida-Georgia border with weak wave moving through
zonal flow aloft. Low temperatures will be in the lower 60s southeast Georgia...middle
60s NE Florida.
Long term /Tuesday through Sunday/...
prefer slightly stronger/faster European model (ecmwf) solution vs weaker/slower
GFS solution...NAM similar to European model (ecmwf) but may be a bit too strong.
Upper system moves eastward over western Gulf Coast region
Tuesday...surface low develops over northern Gulf with northward surge
of Gulf moisture ahead of it. Widespread cloudiness and warm
advection showers will keep high temperatures down in 70s...perhaps
around 80 ocf area.
Interesting scenario Tuesday night into early Wednesday. Upper system
moves eastward...while surface low moves over Florida Panhandle late
Tuesday night and SW/sctrl Georgia by Wednesday morning. NAM soundings
suggest destabilization during Tuesday evening through low-level
moistening and slight middle-level cooling...thus steepening lapse
rate...with elevated cape values exceeding 1000 j/kg. Environment
associated with strong vertical shear. This setup could support
elevated supercells with hail along warm front extending over southern
Georgia/far northern Florida by Wednesday morning. Extent of severe weather threat will
depend heavily on level of instability existing at night. Models
suggest northward surge of 70-72 dewpoints late Tuesday night across
forecast area...except delayed until Wednesday morning on slower GFS. We
will closely monitor this potential event.
Drier conditions for latter part of week through next weekend...with
near or slightly below normal temperatures.
VFR will generally prevail for the next 24 hours. With any afternoon
convection isolated...will use vcsh/vcts. Perhaps some brief MVFR
could be possible if any stronger storms form. Some patchy MVFR
will be possible at gnv late overnight. West/SW winds 12-16 knots with
gusts to 25 knots this afternoon will diminish this evening and veer to
the northwest overnight...and north Monday. Will use vcsh for initial
shower activity by midday Monday.
winds continue to diminish this afternoon...so will lower caution
for the outer waters. Expect conditions to remain under caution
through Tuesday. Flow becomes more east to southeast and increase
in speed Tuesday night/Wednesday as low pressure approaches from
the northern Gulf of Mexico. As the low tracks across southern Georgia
to SC coast Wednesday/Wednesday night and intensifies...winds will shift to
south and southwest. Winds will likely reach advisory criteria
late Wednesday into Thursday after a cold front moves through and
winds shift to westerly. Winds/seas gradually decrease Friday/Sat as
low moves further away from the area.
Rip currents: low risk through Monday.
Preliminary point temps/pops...
amg 63 79 60 74 / 10 10 10 50
ssi 65 72 64 70 / 10 10 10 50
jax 67 79 64 76 / 10 20 30 60
sgj 70 77 66 75 / 20 30 30 60
gnv 69 83 65 78 / 20 40 50 60
ocf 70 84 67 80 / 30 40 50 60