Summer Solstice Arrives Friday
Father’s Day will be partly sunny and warm with high temperatures reaching the middle to upper 80s. Scattered afternoon and evening thunderstorms are possible as well but the day will definitely not be a wash out.
30 Day Departure from Normal Rainfall:
30 Day Rainfall Totals (Departure from Normal) – Courtesy NOAA
More rain is expected on Tuesday as a system passes over the DC Area. The weather during the middle of the week (Wednesday and Thursday) will be spectacular with sunshine and low humidity.
The Summer solstice arrives on Friday, June 21st and several of the mid-range computer models are predicting that warmer weather will begin to infiltrate the Midwest and Eastern seaboard 9 days out (next weekend and beyond).
500 mb Height Anomaly, Image courtesy: TropicalTidbits.com
“Moderate” Risk for Severe Weather Thursday
Image Courtesy: Storm Prediction Center/NOAA
- Uncertainty continues as to whether or not the storms currently in the Midwest are going to survive the trip over the mountains during the overnight hours. They may not and could come through as showers Thursday early morning which would help to stabilize the atmosphere.
- Whether or not there is a widespread severe weather outbreak on Thursday will hinge heavily on how much sunshine there is during the morning and midday hours. While everyone across the DC Region may see storms that produce damaging wind gusts, hail and isolated tornadoes, locations from interstate 95 on east have the highest probability of receiving the heaviest storms.
Thunderstorms currently over the Chicago Area (Wednesday 6PM).
Current HRW model hint that storms may not survive the trip and may come through as a line of showers with brief gusty winds early Thursday morning (pre-dawn).
Storms will likely break out again during the afternoon hours as a cold front approaches the Interstate 95 corridor. Storms may be the heaviest from 95 points south and east.
High Resolution Model Hinting at Possible Derecho Event
- Storms Prediction Center Issues a Moderate Risk for Severe Thunderstorms on Wednesday across the Midwest with a “slight risk” across the Washington Region.
Severe Weather Outlook Wednesday (Image Courtesy: NOAA)
- Damaging Winds, large hail and Tornadoes can’t be ruled out in the Midwest Wednesday with severe weather eventually moving into the Mid-Atlantic Wednesday evening/overnight and Thursday.
- Latest High Resolution Window Models beginning to hint at the possibility of a derecho event.
Image Courtesy NOAA
Image Courtesy: NOAA
- Timing is everything and if these storms don’t march into the DC Area until the pre-dawn hours on Thursday the intensity could weaken with the loss of daytime heating. If the storms move faster and get in here around midnight on Wednesday, they could still remain very potent. Another scenario is that the storms could weaken over the mountains preventing any severe weather until Thursday afternoon, especially across the I-95 corridor points east.
- Bottom Line: Be prepared for a possible widespread severe weather outbreak Wednesday afternoon/overnight and again on Thursday.
Rainfall totals during the last 14 days have been pretty incredible, especially across portions of Culpeper, Orange and Madison counties in Virginia, Fairfax county in Northern Virginia and from the Northern Neck to the eastern shore of Maryland.
14 -Day Observed Precipitation, Courtesy NOAA
A potent upper level low pressure system and disturbance will move across the Washington Region sometime between Wednesday afternoon and Thursday afternoon. As this system approaches, widespread thunderstorms may break out. As wind shear increases (winds that change direction with height) a severe weather outbreak is possible with hail, damaging winds and tornadoes.
A potent disturbance can be seen across the PA/MD border on Thursday afternoon. This disturbance may spark a severe weather outbreak in the warm sector across the DC Region. Image Courtesy NOAA
Surface Map from the GFS shows thunderstorms breaking out on Thursday afternoon:
GFS surface plot for Thursday PM; Image courtesy NOAA
Father’s Day Weekend:
As of now, Saturday is looking spectacular with sunshine, low humidity and a nice northwest breeze.
Father’s Day looks to start out nice with a chance for afternoon thunderstorms (To be determined… still a ways out!)
Image Courtesy: NOAA/WPC
Image Courtesy: NOAA
- Two periods of rain will impact the DC Area over the next 36 hours: One Thursday night and the second associated with the remnants of Andrea Friday morning through the afternoon rush hour.
- Rainfall will generally average one to three inches in the DC Area with the heaviest amounts falling across the Chesapeake Bay.
- Tropical storms can spawn tornadoes and the greatest threat will be in the right, front quadrant of Andrea’s track. This threat will likely remain east of the DC Region from the eastern shore counties towards the beaches of the DEL-MAR-VA.
- The weekend will feature partly sunny skies with isolated thunderstorms during the afternoon hours. Lows will dip into the lower to middle 60s and highs will reach the lower to middle 80s for the Nationals game and various events across downtown Washington.
Slight risk for Severe Thunderstorms (yellow) on Sunday Afternoon (Image courtesy: SPC/NOAA)
Scattered showers and thunderstorms will break out across the Washington Region on Sunday afternoon. Some thunderstorms may become severe with damaging wind gusts and hail.
A cold front will pass through the Washington Area on Monday producing more scattered showers with embedded thunderstorms.
Rainfall totals (Sunday and Monday) will generally average a quarter to one half of an inch with locations receiving the heaviest thunderstorms picking up well over an inch.
48 Hour Rainfall Potential (Courtesy: NOAA/WPC)
Tuesday and Wednesday will feature lower humidity under partly cloudy skies. Unsettled weather may return late in the week as the next system approaches.
Low temperatures: 50 – 60
High temperatures: 75 – 80
Much cooler air will move into the Midwest, New England and Mid-Atlantic during the upcoming work week. (Image courtesy: TropicalTidbits.com)
Here Comes Some Relief from the Pollen
Potential Rainfall Totals Monday through Wednesday Evening (NOAA/WPC)
- A cut off low pressure system will deliver some much-needed rainfall to the Mid-Atlantic Monday afternoon through Wednesday. High temperatures will hold in the middle 60s.
- The rainfall will be steady enough on Monday evening through Tuesday to wash the pollen out of the air bringing relief to anyone suffering from allergies.
- Skies should clear out Thursday and Friday with moderating temperatures (upper 70s and 80s).
