Doug Simonian

Most of the Rain Will Stay South; Some Locally Heavy Rain Still Possible

/by

Good afternoon, everyone! We hope you are enjoying your Friday. Some isolated thunderstorms have developed across the area — particularly across Long Island — where a seabreeze converged with prevailing northeast winds, thus leading to convergence and lift. Some heavy downpours were had with these storms. But with very little wind shear, they rained themselves out and weakened. A few more isolated showers and thunderstorms are still possible across the region for the rest of the afternoon and tonight with subtle boundaries and sheared out vorticity ahead of the main shortwave in the Mid Atlantic, but nothing is expected to be particularly noteworthy.

Currently, the Mid-Atlantic is seeing flooding rains, with frontal forcing, very high dewpoints, training thunderstorm cells, moisture convergence, and a dynamic shortwave all congealing in that area. Rainfall amounts have been 3″+ in one hour in many locations, as a truly unique combination of synoptic forcing and deep, moist convection hits the area. If this shortwave were able to turn northward, a lot of this activity could have hit NYC as well, as some model guidance as recently as yesterday was showing 5″+ of rain for NYC.

Read more

Miguel Pierre

Premium Long Range: A Look at the Western Hemispheric Pattern and Tropics in August

/by

Late last week, we saw our second heat wave of the summer over many parts of the Northeast and Mid-Atlantic region. It may have appeared to some people, that may be we have turned the tide toward more hot and humid pattern for the rest of the summer. But this pattern much cooler and unsettled this week. Now there are increasing indications from several climate phenomena and long-range ensemble guidance of major pattern change now occurring over the Pacific Basin, that will support a cooler pattern, for the Northeast and Mid-Atlantic regions, at least the first couple weeks of August.

Overall Pattern

On the long-range ensemble guidance, the atmospheric pattern changes start out in the Pacific. A large trough will be over parts Southeast Asia and Western Pacific and in turn support a ridge near or just south of the Aleutian Islands and a large trough or upper-level low over more of the Gulf of Alaska and Northeast Pacific. This North Pacific pattern overall will continue to support more profound heat ridge in parts of the Western and Central US. More ridging over Greenland/Davis Strait will also result in a more negative NAO pattern. This entire pattern throughout the Western Hemisphere will on average support deeper troughiness in the Great Lakes and Ohio Valley and stronger Western Atlantic ridge to build over next couple weeks. But we do know ensembles and weeklies in general in the super long-ranges are less reliable. So what climate phenomena is potentially influence this pattern?

Read more

John Homenuk

Eyes on weekend storm as model inconsistency continues

/1 Comment/by

Active weather continued throughout much of the Northeast states Thursday, with transient clouds and showery activity for much of the day as a disturbance in the levels of the atmosphere passed through. This disturbance was relatively weak and, as mentioned, transient in nature, limiting the potential for strong to severe thunderstorm coverage that may have otherwise existed, especially given the presence of instability.

With that said, pleasant conditions gradually returned to the majority of the Northeast states on Friday morning — but it will be short lived.

Read more

John Homenuk

Unsettled Thursday, eyes on weekend coastal storm

/1 Comment/by

Good morning! A beautifully pleasant and calm weather day on Wednesday is behind us, and the weather will take a more transitional and unsettled turn in the Northeast states today. You can thank the weakening grip of a large mid level ridge for that, as its departure will open the door for multiple disturbances to move into the region. High pressure has already begun its shift off the Eastern US coast this morning.

A disturbance in the atmosphere’s mid and upper levels will begin to approach the area this afternoon and evening. The first thought going through many peoples minds will be the potential for strong and severe thunderstorms – but there are several mitigating factors that will be acting against those chances today. Instead, the potential for showers and a few isolated thunderstorms is expected to evolve.

Read more