Scientific Forecaster Discussion
fxus64 klix 260820
Area forecast discussion
National Weather Service New Orleans la
320 am CDT Wed Jun 26 2019
an upper level ridge will build across the southern half of the
country from West Texas to the East Coast. It will be a daily battle
between daytime heating induced convection and subsidence aloft. For
today, the southeastern half looks to be mainly dry outside of a
random storm or 2. The northwestern half could see more scattered
convection late in the day as surface heating erodes the cap. Ample
bouyancy will be available, typical of this time of year, while the
wind field through the column looks to be weaker and less conducive
than yesterday. Model soundings show an inverted v in the lower
levels, suggesting gusty winds will be possible with stronger cells.
Won't completely write off severe storms, but most today should be
sub-severe/Special Weather Statement type storms. Meso and global models are pinging on
the Baton Rouge Metro area for highest pops, so have bumped them up
to 40%. 10 to 30's elsewhere.
Thursday still has the chance to be the driest day of the forecast
period with the European model (ecmwf) showing more subsidence than the GFS, but the
overall synoptic pattern suggests at least some storms will be
possible. Kept the pop forecast similar to the previous with 20 to
30% coverage with storms again developing late but this time coming
in from the northeast/southern MS.
Gradual upper level trough intrusion over the northeastern Continental U.S.
Friday into the weekend will erode the ridge over the Gulf Coast and
southeastern US. This will allow strong daytime heating to produce
numerous afternoon thunderstorms. Therefore, have kept daytime rain
chances upwards of 50 to 60% with storms likely lasting well into
the evening hours. This pattern will spill over into early next week
and possibly longer. The European model (ecmwf) shows another ridge building over the
Easter Gulf by mid week, effectively shunting daytime convection
west. The GFS also has a solution similar to this, albeit a weaker
ridge that doesn't keep probability of precipitation down by much. Tend to prefer the wetter
solution as the GFS has been doing a better job synoptically as of
Generally VFR conditions are expected for this taf cycle. Isolated
pulse thunderstorms are possible today. The highest chances of this
occurring should be within the river parishes affecting the btr
terminal after noon. This will be shown as thunderstorms in the vicinity in prevailing group.
Surface high pressure has moved over the northern Gulf Coast causing
winds to become light and somewhat erratic. The high will move east
of the area by the end of the week as a well established tropical
wave moves west. The wave should begin to affect the coastal waters
Friday with more nocturnal sh/ts development. Winds are expected to
stay rather weak at 10kt but could be as high as 15kt during the
waves transit to the west. Wind direction will change from NE to east
then southeast Friday through Saturday. Wind direction and speed will be
higher and erratic in and around thunderstorm activity. Another sfc
high is then expected to move westward into the north central Gulf
by the start of the new work week.
Dss code: blue.
Activities: river flood warnings
Preliminary point temps/pops...
mcb 92 71 93 71 / 30 20 30 30
btr 93 73 93 72 / 40 20 20 20
asd 93 74 94 73 / 20 20 30 30
msy 93 77 93 76 / 10 20 20 20
gpt 91 76 93 75 / 10 20 30 30
pql 94 73 94 73 / 10 20 30 30