Lexington Weather

Lexington, Massachusetts, USA

57°F

5/17/2024 8:36am

Lexington Conditions: Overcast
Temperature: 57.0°F / 13.9°C
Dew Point: 55.2°F
Relative Humidity: 94%
Wind: N Calm, 10-min avg: 1 mph, gust: 3 mph
Barometer: 29.97 in Steady
Visibility: 10 miles
Rain Today: 0.00 in

Area Forecast Discussion
for North Platte, NE

        
000
FXUS63 KLBF 111145
AFDLBF

Area Forecast Discussion
National Weather Service North Platte NE
645 AM CDT Sat May 11 2024

.KEY MESSAGES...

- Generally near or above normal temperatures for the next week with 
no widespread frost anticipated

- A few showers/storms south today, then more widespread tomorrow 
afternoon with little to no severe weather threat

- More low end (<30%) chances of precip throughout the week,
  although a greater potential for more widespread thunder
  (60%+) Tuesday evening

&&

.SYNOPSIS...
Issued at 405 AM CDT Sat May 11 2024

An upper level closed low spins near Las Vegas, while Nebraska lies 
on the western periphery of a more prominent trough digging through 
the Great Lakes and the Chesapeake. At the surface, high pressure 
has settled onto the Great Plains in the wake of a quick-passing 
cool front.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 405 AM CDT Sat May 11 2024

Today and tonight... The surface high drifts east, resulting in 
downslope west flow early in the day to become more southerly later 
on for the region. The southerly low level return flow will help 
pull moisture into Nebraska, as shown by dew points rising into the 
mid/upper 40s by tonight. A developing lee side surface low will add 
to the forcing ahead of the approaching upper low, and an isentropic 
upglide regime takes hold. While the bulk of the rain shower 
activity will take place in CO/KS, some showers and perhaps a storm 
should be able to spread into southwest Neb toward sunset. A few 
showers will also continue into the overnight hours as the upper low 
eventually reaches eastern CO. Thunder parameters are very weak, and 
severe weather is not anticipated, as MUCAPE will be limited to 500 
j/kg and deep layer shear 20 kts. For max temps, bumped values up a 
couple degrees over the previous forecast to account for fair skies 
for at least the first half of the day and modest warm air advection 
at H85. Guidance has trended slightly warmer, reflecting the 24 hr 
temp changes of 3-4C at H5. Highs range from mid 70s in the 
panhandle to near 80F in central Neb. Increased cloud cover tonight 
should hold lows to the mid 40s (west) to lower 50s (east).  

Tomorrow... The main upper low, as well as the surface low, cross 
into western Kansas by the afternoon. Meanwhile, a clipper-like 
system comprising a low and attendant cool front, race south from 
the Prairie Provinces and reaches the SD/NE border by sunset. Low 
level flow flips to southeasterly, which increases the moisture 
advection further. Despite a weaker shear profile, instability seems 
to increase across the Sandhills with mid-level lapse rates near 7 
C/km and MU values nearing 1000 j/kg in spots. Short term model 
guidance locks on to iso/sct showers becoming more widespread in the 
afternoon. The severe weather threat still appears low, but pockets 
of heavier precip is definitely in play. Recycled cool air at H85 
and thicker cloud cover will keep max temps cooler in the south 
compared to the north. The NBM envelope spread widens, so stayed 
near the median values given the higher uncertainty. Highs should 
range from upper 60s south of I-80 to near 80F along the SoDak 
border.

&&

.LONG TERM /MONDAY THROUGH FRIDAY/...
Issued at 405 AM CDT Sat May 11 2024

Continued forcing and remnant moisture near the upper low will keep 
a few rain showers around on Monday, but a stronger cool front 
presents a more significant and widespread shot of moisture on 
Tuesday. Will need to monitor for a window of strong or severe 
storms across the Sandhills during the afternoon and evening. 
Guidance points to a ribbon of higher CAPE values riding up the Hwy 
83 corridor, while a newly approaching upper trough increases the 
deep layer shear component. To round out the week, upper flow 
becomes nebulous but a couple more surface boundaries slide through 
the region. The forecast maintains periodic low end (20-30%) PoP. As 
for temps, an H85 thermal ridge kicks into gear on Tuesday ahead of 
the cold front. Guidance ranges from 15-20C in the Sandhills, which 
could translate to lower/mid 80s in the south and upper 70s to the 
north. The front presents a brief setback Wed and Thu, but highs 
should rebound to the 70s/80s by the end of the week. Even with the 
frontal passage, morning lows really don't dip below 40F this
week.

&&

.AVIATION /12Z TAFS THROUGH 12Z SUNDAY/...
Issued at 632 AM CDT Sat May 11 2024

VFR conditions continue over the forecast period. Winds will be
out of the west to southwest around 5 to 10 kts throughout the
day into tonight. Skies will remain mostly clear over the next
24 hours. There is a slight chance of a shower or thunderstorm 
across southwest Nebraska.

&&

.LBF WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SYNOPSIS...Snively
SHORT TERM...Snively
LONG TERM...Snively
AVIATION...Gomez