  We report the discovery of a velocity coherent, funnel shaped ^13CO emission
feature in the Galactic centre (GC) using data from the SEDIGISM survey. The
molecular cloud appears as a low velocity structure (V_LSR=[-3.5, +3.5] km/s)
with an angular extent of 0.95{\deg} x 1{\deg}, extending toward positive
Galactic latitudes. The structure is offset from Sgr A* toward negative
Galactic longitudes and spatially and morphologically correlates well with the
northern lobe of the 430 pc radio bubble, believed to be the radio counterpart
of the multiwavelength GC chimney. Spectral line observations in the frequency
range of 85-116 GHz have been carried out using the IRAM 30 metre telescope
toward 12 positions along the funnel-shaped emission. We examine the ^12C/^13C
isotopic ratios using various molecules and their isotopologues. The mean
^12C/^13C isotope ratio (30.6+-2.9) is consistent with the structure located
within inner 3 kpc of the Galaxy and possibly in the GC. The velocity of the
molecular funnel is consistent with previous radio recombination line
measurements of the northern lobe of radio bubble. Our multiwavelength analysis
suggests that the funnel shaped structure extending over 100 pc above the
Galactic plane is the molecular counterpart of the northern GC chimney.
