textproduct: Raleigh

WHAT HAS CHANGED

As of 130 PM Tuesday...

* Wind gusts and highs were raised for Wednesday.

KEY MESSAGES

As of 130 PM Tuesday...

1) Very warm temperatures through Wednesday with an airmass typical of early July.

2) A Strong cold front brings showers Thursday, with a low-end threat for strong to severe storms in our southeast counties.

3) Another strong cold front moving through the region Sunday night and Monday may bring another low-end severe weather threat, mainly in our southeast. Well below normal temperatures are possible next week.

DISCUSSION

As of 130 PM Tuesday...

KEY MESSAGE 1... Very warm temperatures through Wednesday with an airmass typical of early July.

The morning clouds and some patchy light rain has largely dissipated this afternoon with full sunshine for the rest of the afternoon. Some weak energy near the NC mountains will track east into the early evening hours. This energy could bring a few patchy showers over the southern Piedmont and Sandhills, but most CAM solutions keep the area dry.

The main story the rest of today and especially tomorrow is very warm to near hot temperatures. Afternoon highs today will top out in the low to middle 80s, some 20-25 degrees above normal. Tomorrow, low-level thicknesses rise to around 1410m, typical of early July. As such, we raised highs on Wednesday with the latest guidance suggesting widespread upper 80s to near 90, warmest in the Sandhills. These highs are likely to break records (see climate section). Wind gusts tomorrow afternoon will pick up ahead of the frontal system approaching late Wed night. Gusts from the southwest of 25 to 30 mph are possible, with some infrequent gusts to 35 mph at times.

KEY MESSAGE 2... A Strong cold front brings showers Thursday, with a low-end threat for strong to severe storms in our southeast counties.

Guidance continues to be in good agreement that a strong cold front will move through during the day on Thursday. Similar to the prior forecast, much of the rain/showers will occur from early Thu morning into early Thu afternoon. Because the front is pushing through in the morning hours, instability continues to be a limiting factor for strong storm potential. SPC continues to mention limited heating and poor lapse rates precluding strong destabilization. If stronger heating were to be realized, it would be favored over the eastern Sandhills to the Coastal Plain, where some AI convective models continue to indicate a low-end threat. Rainfall amounts look similar to what we have been discussing prior, with a quarter to one half inch of rain, with the low-end around a tenth to two tenths of an inch. Behind the front, some gusts from the NW may range from 25-30 mph in the afternoon to early evening, but should dissipate Thu evening/night as cool high pressure builds in from the west.

KEY MESSAGE 3... Another strong cold front moving through the region Sunday night and Monday may bring another low-end severe weather threat, mainly in our southeast. Well below normal temperatures are possible next week.

After the passage of the cold front on Thursday, temperatures will drop closer to normal on Friday, before increasing back to around 10- 15 degrees above normal by Sunday. The next best chance of rain and possible embedded storms will be Sunday night into Monday. LREF cluster analysis suggests that pre-frontal rain may start as early as late Sunday afternoon, with the rain with the front occurring later Sunday and overnight. In the pre-frontal rain Sunday afternoon, a few storms could be stronger as temperatures are expected to be in the 70s, with dewpoints approaching 60. Cluster analysis is also showing a few different solutions for the timing of the frontal passage, with 1 of 4 clusters showing the front moving through Monday afternoon instead of Monday morning. If this were to occur, severe chances would be larger on Monday as there will be more instability with additional daytime heating. However, at this time, most of the model solutions are showing an earlier frontal passage, lessening the chances for stronger storms. Also, if the cold air is able to get in faster and precipitation is slow to exit, a brief period of light snow may be possible Monday night. However, only 1 of 4 clusters show 20% of at least 0.1 inch of snow, meaning that this is not likely at this time.

The front is expected to drop temperatures by around 20 degrees, with lows dropping near to below freezing in the northwest on Monday night and then everywhere Tuesday night. Highs also look like they may only rise into the 40s to low 50s Tuesday afternoon. This would be about 15-20 degrees below normal for this time of year.

AVIATION /18Z TUESDAY THROUGH SUNDAY/

As of 100 PM Tuesday...

VFR conditions are expected to prevail across central NC through much of the 24 hour TAF period. Some guidance suggest patchy fog or stratus early Wednesday morning, but increasing high clouds should help mitigate this. Light southwesterly flow through tonight will strengthen on Wednesday with sustained 10-15kt gusting up to 25-30kt.

Outlook: A strong cold front bringing showers and possibly a few thunderstorms, sub-VFR conditions, and gusty winds on Thursday. VFR returns Fri into Sat.

CLIMATE

Record High Temperatures:

March 10: KGSO: 78/2016 KRDU: 81/1974 KFAY: 84/1974 March 11: KGSO: 86/1967 KRDU: 85/1925 KFAY: 87/1925

Record High Minimum Temperatures:

March 10: KGSO: 58/2016 KRDU: 57/2020 KFAY: 65/1964 March 11: KGSO: 62/2016 KRDU: 63/2016 KFAY: 63/2016

RAH WATCHES/WARNINGS/ADVISORIES

None.