Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/20/21
Area Forecast Discussion
National Weather Service Miami FL
722 PM EDT Fri Mar 19 2021
Main story for the taf cycle will be gradually veering winds from
the W/NW overnight to N/NE by the end of the period, with the
exception of KAPF. While drier conditions should keep terminals
mostly dry, have included VCSH for the east coast tomorrow to
account for the possibility of some Atlantic SHRA moving inland.
Likewise, conditions should be primarily VFR with intermittently
lower cigs possible associated with SHRA.
The weak cold front that pushed across the area today now resides
to our south over the Florida Straits. At this time, the forecast
remains in good shape with northwesterly flow behind the front
allowing for cooler and drier air to trickle into South Florida
through the overnight hours. Outside of a few possible spotty
showers along the east coast, more pleasant and spring-like
conditions will be enjoyed across South Florida tomorrow.
.PREV DISCUSSION... (Issued 245 PM EDT Fri Mar 19 2021)
Today through Saturday...
The tail end of a cold front is current passing through the region,
with scattered convection lingering ahead of the front over the
Atlantic waters. As the front clears the area today, westerly winds
will veer towards the NW by tonight. This will allow for cooler and
drier air to settle into the region, and should keep the area fairly
dry for tonight with the exception of the offshore Atlantic waters,
where scattered showers are possible overnight. Cannot rule out a
thunderstorm over the Atlantic waters through the day as well, as
RAP mesoanalysis data reveals ML CAPE values of 1000-1500 J/kg over
the Atlantic waters.
By tomorrow, a weak post-frontal surface trough oriented from SE to
NW remains positioned along the Atlantic coastline. This introduces
a modest coastal convergence setup, with NE winds over the waters
and NNE winds along the immediate coastline. With a neutral synoptic
environment that favors neither rising or sinking motion and the
aforementioned coastal moisture convergence, isolated/scattered
showers may develop across coastal metro portion of Miami-Dade,
Broward, and Palm Beach Counties. These showers will be mostly of
the garden variety, and impacts will be limited to locally gusty
Maximum temperatures will cool down considerably compared to
previous days. Forecast maximum temperatures today may reach the
lower/mid 80s, however by tomorrow with the cooler NW/N flow,
maximum temperatures should be seasonable, with maximums in the
upper 70s region-wide.
Saturday Night through Friday...
A developing low pressure system in the Northwestern Bahamas aided
by a 500mb trough digging southwards across the Southeastern United
States, will create cyclogenesis over the Northwestern Bahamas and
bring cyclonic flow to our area as a result on Sunday. This cyclonic
flow may allow for the advection of increased moisture and a few
coastal showers along portions of the Atlantic coast of South
Florida. The main concern with this offshore low pressure system
continues to be the potential of elevated swell from this feature
over the next week which will result in hazardous marine and beach
conditions for the atlantic and east coast beaches over the next
several days. As the surface feature begins to move northeastwards
in response to the eastward progression of the 500mb trough, rain
chances will decrease during Sunday evening into Monday.
The departure of this feature will allow for a ridge of high
pressure to build into our region during the early part of the week,
which will bring another period of quiet and benign weather to our
area. As diurnal onshore flow returns along both coasts under the
ridge of high pressure, a gradual warming trend will continue
through late week.
Drier conditions will continue to filter into the region as a weak
cold front pushes away from South Florida. Likewise, winds will
continue to gradually becoming NW through the evening and then
N/NE tomorrow. While VFR conditions should prevail, can`t rule
out brief bouts of MVFR cigs until the front fully clears.
A frontal boundary will continue to slowly progress into the western
Atlantic waters. This will serve as a foci for scattered showers and
isolated thunderstorms to develop, which may allow for locally
higher wind gusts and perhaps an isolated waterspout within any
stronger storm. The eastward movement of the front will allow for
winds to veer out of the NW by tonight, and then out of the N/NE by
tomorrow. A surface low associated with this frontal boundary
undergoes modest development as it moves into the offshore waters.
This will allow for a NW swell to develop on the back-end of this
feature, which is forecast to propagate towards the Atlantic
coastline for the latter part of the weekend. Dangerous marine
conditions may evolve from this, with wave heights from 6 to 10 ft
possible along the Atlantic nearshore waters.
A passing cold front will cause winds to shift from the W towards
the NW tonight and eventually N/NE by tomorrow morning. This will
lead to a moderate risk of rip currents across the Gulf Coast
beaches today. The risk of rip currents will increase over the
Atlantic beaches by the second half of the weekend into early next
week as a northeasterly swell develops.
.PRELIMINARY POINT TEMPS/POPS...
Miami 63 80 64 81 / 10 20 20 20
West Kendall 58 82 61 82 / 0 10 20 10
Opa-Locka 61 79 62 80 / 10 20 20 20
Homestead 58 79 61 80 / 0 10 20 10
Fort Lauderdale 64 80 64 81 / 10 20 20 20
N Ft Lauderdale 63 78 63 79 / 10 20 20 20
Pembroke Pines 61 80 62 81 / 10 20 20 20
West Palm Beach 63 78 62 79 / 10 20 20 20
Boca Raton 64 79 63 80 / 10 20 20 20
Naples 56 76 58 76 / 0 0 0 0
Tonight/Saturday and Marine...Bhatti
Saturday Night through Friday...Hadi
Visit us at weather.gov/miami
Follow us on Facebook and Twitter at:
Area Forecast Discussion...UPDATED
National Weather Service Reno NV
746 PM PDT Fri Mar 19 2021
Quick update to increase rain chances significantly east of
Lovelock and Fallon. Front is expected to reform there overnight
with good frontogenetical forcing into central Nevada. HREF and
HRRR are showing this development well in line with operational
GFS/NAM. As current radar and satellite trends are showing this
band developing quite well, have increased the pops and rain
amounts there. The band looks to hang around until just after
midnight before pushing east into the rest of central and eastern
Nevada. Rainfall amounts up to 1/3 inch here (more potential in
Elko`s area) with a few inches of snow above 7000 feet or so in
the mountains. X
.PREVIOUS DISCUSSION... /Issued 119 PM PDT Fri Mar 19 2021/
Rain and snow showers along with gusty winds continue through
tonight. A few light snow showers are likely to linger on
Saturday. It will remain cool over the weekend followed by the
potential for a couple of quick moving storms Monday and Thursday.
The main Pacific moisture tap from our ongoing system is sliding
south early this afternoon. Rain and snow showers will continue
through tonight, with the highest chances in the Sierra and
northeast California as the upper trough moves onshore. Snow
levels are expected to lower by late afternoon into this evening
as the cold core of the low moves in overhead. Brief snow
accumulations on Sierra roadways are possible, but are likely to
be short-lived until after sunset as roads remain rather warm.
Overnight, travel difficulties will be likely through the
aforementioned areas. Isolated showers will be possible area-wide
Saturday as the trough transverses across the region, but
additional accumulation will be negligible with road impacts
unlikely. It will, however, be rather chilly on Saturday with
temperatures about 10 degrees below normal.
Winds will remain rather gusty today along the Sierra Front,
particularly along US-395 from Reno south and US-95 near Walker
Lake. Travel may be difficult for high profile vehicles and we are
getting plenty of report of turbulence and wind shear for aviation
interests. Winds will become lighter tonight into Saturday with
relatively light N-NE flow for the weekend. Northwest winds look
to increase once again Monday into Tuesday, per NBM guidance, but
EPS meteograms are all showing a rather run of the mill type event
for speeds with gusts peaking around 25-40 mph.
Ensemble clusters are in better agreement for the early part of next
week keeping the ridge offshore in the eastern Pacific, which
allows for weak systems to drop out of the north. Better agreement
exists for the main storm track to be just to the east, so while
a few light showers are possible, GEFS/EPS both agree that liquid
totals have a 90% likelihood of remaining under a tenth of an inch
for the Sierra and western Nevada. While there is certainly still
positional spread in the ensemble clusters, the leading solution
keeps the ridge offshore with yet another wave dropping out of
the northwest on Thursday. This could mean another round of light
precipitation along with the anticipated warm-up being further
delayed. At this point, however, confidence in the exact position
of this feature and associated rain/snow and temperatures is low
given the spread in guidance. -Dawn
Winds will remain gusty through tonight, especially at ridge
tops. For terminals along the Sierra Front from KRTS south to KMMH
gusts 25-40 kts are likely. These winds will create enhanced
turbulence and LLWS especially over the Sierra and Sierra Front.
A low-pressure trough moving onshore will continue to bring
chances for snow showers through Saturday, but on runways snow
accumulations greater than an inch are unlikely.
Unsettled weather continues next week, with periods of gusty
winds and chances for snow or rain showers, but the storms are
expected to be on the weak-to-moderate end of the spectrum. JCM
NV... Lake Wind Advisory until 8 PM PDT this evening for Lake Tahoe in
CA...Wind Advisory until 8 PM PDT this evening CAZ073.
Lake Wind Advisory until 8 PM PDT this evening for Lake Tahoe in
For more information from the National Weather Service visit...