Area Forecast Discussion
Issued by NWS North Platte, NE

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
067
FXUS63 KLBF 242052
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
352 PM CDT SUN JUL 24 2016

.SHORT TERM...(This evening through Monday)
Issued at 331 PM CDT Sun Jul 24 2016

Surface high pressure will be centered across eastern Nebraska
tonight, with light east to southeast winds across western and
north central Nebraska on the western side of the high pressure
center. The combination of subsidence and drier air advecting into
the region will allow for a very comfortable night, with lows
dropping into the upper 50s to lower 60s. There will be a small
chance for showers and thunderstorms across far southwest Nebraska
this evening, as ample instability within upslope flow may allow
for some thunderstorms to survive off the higher terrain to the
west.

Return southeast flow develops Monday as the high pressure center
moves off to the east into Iowa. Dew points will once again be on
the rise, with mid 60s by late afternoon advecting into southwest
Nebraska. Scattered late afternoon thunderstorms are expected to
develop once again in the higher terrain areas to the west within
increasingly moist upslope flow. Southeast flow beneath northwest
flow aloft will set up a favorable shear environment which would
support right moving supercell structures. Any of this activity
though should remain west of the area until tomorrow evening.

.LONG TERM...(Monday night through Sunday)
Issued at 331 PM CDT Sun Jul 24 2016

Monday Night through Tuesday Night: The 500 hPa high near the
four corners will build to about 595 dam to begin the period as
minor ridging occurs over western and north central NE Monday. A
mid-level shortwave trough will round the ridge from north
central WY to central SD/far north central NE beginning late
afternoon Monday into early Tuesday providing weak large scale
ascent. During the day, a lee-side trough will develop and deepen
near the Front Range, meanwhile there will be decent moisture over
western NE at the surface and at low-levels due to the predominant
S-SSE flow. Current thinking is that the best chances for
convective development will be north of and along I-80, and as
development occurs over the higher terrain that then moves
east into western Nebraska. There will be a marginal chance for
isolated strong to severe thunderstorms, mainly over the northwest
quad of the CWA. Wherein, decent instability will combine with
about 30-45 kts of 0-6 km bulk shear to promote organized
multicells, some supercells possible. Otherwise, storms may linger
and persist overnight, mainly over north central NE.

Tuesday will be another warm day with increased chances for
showers and thunderstorms in the afternoon through Tuesday night.
Surface lee-side trough near the Front Range will deepen during
the day. Not much change to the large scale pattern with the 500
hPa high by the Four Corners region moving slightly west more into
the southwest US. Meanwhile, another disturbance aloft rounds the
broad ridge into western NE. There will be decent moisture in the
BL and lower-levels, more so compared to Monday night, as
moisture will be better distributed across the CWA, especially in
the BL and surface. Instability will be decent and bulk shear will
be supportive of multicells, and possible some supercells. The
best environment looks to be across the northern two-thirds of the
CWA at this time. As such, there will be marginal risk of strong-
severe storms, and this is highlighted in the SPC Day 3 outlook
with the entire CWA in the MRGL risk area. Guidance suggests and
supports convection lingering and continuing overnight with the
assistance of the nocturnal low-level jet that strengthens Tue
evening/early Wed morning. Notably, the NAM12 QPF and placement
would suggest an organized MCS developing and going through the
middle of the CWA. GFS QPF also supports a similar story, however,
the guidance is more north and east with respect to its QPF
placement. Current thinking is that there is good potential for
overnight convection Tuesday Night. Moderate-heavy rainfall will
be a concern given PW ~1.25 to 1.5 and decent 850 hPa moisture
transport. There is still some uncertainty in regard to location
and coverage Monday Night and Tuesday, so further tuning will be
necessary as we get closer.

Wednesday through Sunday: A cooling trend will begin Wednesday as
a weak cold front will gradually push south into much of the CWA
during the day. This will allow cooler air to filter into the CWA,
at least across the northeast half. However, the southwest half of
the CWA will still see highs mainly in the far upper 80s to lower
90s. The cooling trend will continue Thu and Fri with highs in the
80s, with lower to mid 80s north of and along I-80. Warmer
temperatures return Sat and Sun - highs Sunday are forecast into
the lower 90s across much of the CWA. There will be increased
chances of showers and Thunderstorms across the forecast area
Wednesday through Friday night as multiple disturbances round the
500 hPa high over southwest US as northwest flow prevails at the
mid-levels.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1251 PM CDT Sun Jul 24 2016

A few isolated high based showers and thunderstorms will be
possible this afternoon and tonight, otherwise expect VFR at all
locations with easterly surface winds at 5 to 10 KTS.


&&

.LBF Watches/Warnings/Advisories...
None.
&&

$$

SHORT TERM...Taylor
LONG TERM...ET
AVIATION...Taylor



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.