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Area forecast discussion 
National Weather Service Great Falls Montana
1025 PM MDT Mon Mar 30 2015

Updated aviation discussion

Update...
a ridge of high pressure remains across the region. Dry air
associated with the ridge will continue the mostly clear skies.
Winds have died down and should remain in the current range
overnight most areas - before increasing again on Tuesday. The
forecast is on target so no update tonight. Db

&&

Aviation...
updated 0425z.
Expect ceilings above 15000 ft tonight into Tuesday morning. The
main weather feature affecting the tafs will be a cold front which
will move into kctb around 16z..khln and kgtf around 19z..kbzn and
khvr around 21z..and klwt around 22z. Gusty westerly winds will
develop behind the front and winds will be especially gusty over the
northwest plains where gusts could reach 55 kts. Have fair
confidence in frontal timing and forecast winds in the tafs. Would
not be surprised if winds are even stronger than what is in the tafs
for a brief time during the late afternoon and evening. Scattered
showers and very isolated thunderstorms will develop during the
afternoon mainly near and southeast of a line from khvr to kgtf to
khln. Conditions should remain VFR in the showers and thunderstorms
but wind gusts to 40 kts could be associated with them. Then in the
evening a band of showers will spread from southwest Montana to
central Montana. Again think VFR conditions will be associated with
them. Gusty winds westerly winds will continue into the evening with
little if any drop in wind speeds. Blank

&&

Previous discussion...
/issued 548 PM MDT Mon Mar 30 2015/

Tonight through Wednesday...satellite indicates our next low
pressure trof currently approaching the West Coast. Jet associate
with the trof will push across The Rockies Tuesday morning and keep
winds behind the cold front strong...mid-level winds will strengthen
as this system moves east tonight and these winds will remain near
40kts through Wednesday. The front associated with this low pressure
system will cross The Rockies early Tuesday, 6-9am, and move through
Havre, Lewistown, and Bozeman during the afternoon. The air mass
will destabilize tonight and Tuesday as heights fall ahead of this
system. East and southwest portions of the County Warning Area will become the most
unstable and a chance of thunderstorms will develop during the
afternoon. The low pressure center will move into Saskatchewan and
the surface pressure gradient to the southwest will remain very
tight late Tuesday and Tuesday night. Especially strong winds are
expected northeastern zones. The combination of possible lightning
strikes and strong wind will create fire weather concerns and a red
flag warning has been issued for Tuesday afternoon across the
eastern zones. Wednesday begins a period of broad cyclonic flow
aloft and a cool, unsettled air mass which will keep showers in the
forecast through the day. Temperatures will be much cooler and
generally remain near or below seasonal normals. Zelzer

Wednesday night through Monday...medium range period opens with an
upper trof exiting the area to the east. Isolated snow showers will
continue overnight Wednesday. By Thursday, a moist and somewhat
unstable northwest flow aloft returns and scattered showers will
develop over the area by afternoon. Precipitation amounts will be on
the light side across the plains and the highest amounts will be
confined to the mountains of southwest Montana. Upper ridging builds
over the area Friday and Saturday bringing generally dry
conditions though isolated showers will be possible over the high
country of southwest Montana. Easter Sunday finds another upper trof
approaching western Montana. The models are leaning toward scattered
rain and/or snow showers for Sunday and Monday. At this point in
time, have kept pops low for this weekend event and will await
forthcoming model runs to further clarify the event. Temperatures
will remain near or slightly above seasonal averages through the
period.

&&

Preliminary point temps/pops...
gtf 44 71 35 52 / 0 20 40 40
ctb 42 62 33 49 / 0 20 30 30
hln 40 69 33 52 / 0 20 40 30
bzn 35 74 28 51 / 0 30 60 40
wey 29 61 20 44 / 0 20 60 30
dln 40 70 28 48 / 0 20 50 40
hvr 36 73 34 55 / 0 20 30 40
lwt 41 75 34 50 / 0 20 50 30

&&

Tfx watches/warnings/advisories...
red flag warning from noon to 9 PM MDT Tuesday Blaine...
Broadwater...Cascade...central and southern Lewis And Clark...
Chouteau...Fergus...Gallatin...hill...Jefferson...Judith Basin...
Madison...Meagher.

High wind watch from Tuesday afternoon through late Tuesday
night northern Rocky Mountain front.

&&

$$

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